Terminal apparatus

ABSTRACT

A terminal apparatus includes a control information detection unit configured to detect first and second DCI, and a transmitter configured to perform UL data transmission based on the first DCI or cancel a resource allocated in the second DCI. A UL grant using the first DCI is detected, when performing UL data transmission based on the UL grant, after the data transmission, a first timer for a corresponding HARQ process is started and a second timer is stopped, and when the first timer expires, the second timer for a HARQ process is started. When cancellation of the UL data transmission using the second DCI is detected, at a timing for the data transmission canceled, the second timer is restarted in a case that the first timer expires and the second timer is running, and the second timer is started in a case that the second timer is not running.

FIELD

The present disclosure relates to a terminal apparatus.

This application claims priority based on JP 2018-086484 filed on Apr.27, 2018, the contents of which are incorporated herein by reference.

BACKGROUND

In recent years, 5th Generation (5G) mobile telecommunication systemshave been focused on, and a communication technology is expected to bespecified, the technology establishing MTC mainly based on a largenumber of terminal apparatuses (Massive Machine Type Communications;mMTC), Ultra-reliable and low latency communications (URLLC), andenhanced Mobile BroadBand (eMBB). The 3rd Generation Partnership Project(3GPP) has been studying New Radio (NR) as a 5G communication techniqueand discussing NR Multiple Access (MA).

In 5G, Internet of Things (IoT) is expected to be established thatallows connection of various types of equipment not previously connectedto a network, and establishment of mMTC is an important issue. In 3GPP,a Machine-to-Machine (M2M) communication technology has already beenstandardized as Machine Type Communication (MTC) that accommodatesterminal apparatuses transmitting and/or receiving small size data (NPL1). Furthermore, in order to support data transmission at a low rate ina narrow band, standardization of Narrow Band-IoT (NB-IoT) has beenconducted (NPL 2). 5G is expected to accommodate more terminals than theabove-described standards and to accommodate IoT equipment requiringultra-reliable and low-latency communications.

On the other hand, in communication systems such as Long Term Evolution(LTE) and LTE-Advanced (LTE-A) which are specified by the 3GPP, terminalapparatuses (User Equipment (UE)) use a Random Access Procedure, aScheduling Request (SR), and the like, to request a radio resource fortransmitting uplink data to a base station apparatus (also referred toas a Base Station (BS) or an evolved Node B (eNB)). The base stationapparatus provides uplink grant (UL Grant) to each terminal apparatusbased on an SR. In a case that the terminal apparatus receives an ULGrant as control information from the base station apparatus, theterminal apparatus transmits uplink data using a prescribed radioresource (referred to as Scheduled access, grant-based access, ortransmission by dynamic scheduling, and hereinafter referred to asscheduled access), based on uplink transmission parameters included inthe UL Grant. In this manner, the base station apparatus controls alluplink data transmissions (the base station apparatus knows radioresources for uplink data transmitted by each terminal apparatus). Inthe scheduled access, the base station apparatus can establishOrthogonal Multiple Access (OMA) by controlling uplink radio resources.

5G mMTC includes a problem in that the use of the scheduled accessincreases the amount of control information. URLLC includes a problem inthat the use of the scheduled access increases delay. Use of grant freeaccess (also referred to as grant less access, Contention-based access,Autonomous access, Resource allocation for uplink transmission withoutgrant, type 1 configured grant transmission, or the like, andhereinafter referred to as grant free access) and semi-persistentscheduling (SPS, also referred to as Type 2 configured granttransmission, or the like) is under study. In the grant free access, theterminal apparatus transmits data without performing random accessprocedure or SR transmission and without performing UL Grant reception,or the like (NPL 3). In the grant free access, increased overheadassociated with control information can be suppressed even in a casethat a large number of devices transmit small size data. Furthermore, inthe grant free access, no UL Grant reception or the like is performed,and thus, the time from generation to transmission of transmission datacan be shortened. In the SPS, some of the transmission parameters arenotified by way of higher-layer control information, and transmissionparameters not notified by the higher layer and an UL Grant foractivation indicating allowance of use of a periodic resource arenotified to enable the data transmission.

On the other hand, in a downlink, a resource allocated for datatransmission in eMBB can be used for data transmission in URLLC. Thebase station apparatus notifies a destination UE in the downlink eMBB ofPre-emption control information, and uses a pre-empted resource for thedownlink URLLC data transmission. On the other hand, the terminalapparatus that detects the Pre-emption control information for aresource scheduled for downlink data reception determines that there isno downlink data addressed to the terminal apparatus itself in theresource specified by the Pre-emption. Multiplex of eMBB and URLLC databetween different terminal apparatuses in the uplink is also understudy. In addition, multiplex of eMBB and URLLC data in a case that oneterminal apparatus has traffic of eMBB and URLLC is also under study.

In the case of multiplex of eMBB and URLLC data between differentterminal apparatuses (Inter-UE), the base station apparatus can notify,in advance, of changing a radio resources scheduled in the UL Grant foreMBB uplink data transmission to for URLLC data transmission using a DCIformat. In this case, the terminal apparatus scheduled with the radioresource for eMBB uplink data transmission cannot use at least a radioresource used for URLLC data transmission by another terminal apparatus.Here, the terminal apparatus may stop the data transmission afterdetecting the notification of the radio resource used for the URLLC datatransmission by another terminal apparatus using the DCI. In a case thatthe terminal apparatus stops the data transmission in response to thenotification of the radio resource used for the URLLC data transmissionby another terminal apparatus using the DCI, the base station apparatusand the terminal apparatus known that the data transmission is stopped,and thus, may not transmit the ACK/NACK.

CITATION LIST Non Patent Literature

-   NPL 1: 3GPP, TR36.888 V12.0.0, “Study on provision of low-cost    Machine-Type Communications (MTC) User Equipments (UEs) based on    LTE,” June 2013-   NPL 2: 3GPP, TR45.820 V13.0.0, “Cellular system support for    ultra-low complexity and low throughput Internet of Things (CIoT),”    August 2015-   NPL 3: GPP, TS38.214 V15.1.0, “Physical layer procedures for data    (Release 15),” March 2018

SUMMARY Problem

In a case that the base station apparatus does not transmit the ACK/NACKto the terminal apparatus stopping the data transmission, the terminalapparatus needs to wait for the DCI to retransmit the data stopped fromtransmission. However, in a case that the data transmission is stoppedby way of the DCI from the base station apparatus, a timer for waitingfor the DCI is not started, and the terminal apparatus has a problemthat a period of waiting for the DCI is not configured. Furthermore,there is a problem in that the power consumption increases in a casethat a SR is transmitted due to the data stopped by the terminalapparatus from transmission.

An aspect of the present disclosure has been made in view of suchcircumstances, and an object thereof is to provide a terminal apparatuscapable of implementing a procedure efficient in retransmission of datain a case the data transmission is stopped.

Solution to Problem

To address the above-mentioned problems, a terminal apparatus accordingto an aspect of the present disclosure is configured as follows.

An aspect of the present disclosure is a terminal apparatus forcommunicating with a base station apparatus, the terminal apparatusincluding a control information detection unit configured to detect afirst DCI format and a second DCI format, and a transmitter configuredto perform uplink data transmission based on the first DCI format orcancel a resource scheduled, by using the second DCI format, wherein thecontrol information detection unit detects an uplink grant for theuplink data transmission using the first DCI format, in a case ofperforming corresponding uplink data transmission based on the uplinkgrant, the transmitter, after the uplink data transmission, starts afirst timer for a corresponding HARQ process and stops a second timerfor the corresponding HARQ process, and in a case that the first timerexpires, the transmitter starts the second timer for the correspondingHARQ process, and in a case that cancellation of the uplink datatransmission based on the uplink grant using the second DCI format isdetected, the transmitter, at a timing for the corresponding datatransmission canceled, restarts the second timer in a case that thefirst timer for the corresponding HARQ process expires and the secondtimer is running, and starts the second timer in a case that the secondtimer is not running.

In an aspect of the present disclosure, different periods are configuredfor a second timer configured to start after the first timer expires andfor a second timer configured to start at the timing for thecorresponding data transmission canceled.

In an aspect of the present disclosure, a third timer is provided, thethird timer being configured to start in a case that the uplink grantusing the first DCI format is detected, and in a case that cancellationof the uplink data transmission based on the uplink grant using thesecond DCI format is detected, the third timer is restarted.

In an aspect of the present disclosure, different periods are configuredfor a third timer configured to start in a case that the uplink grantusing the first DCI format is detected and a third timer configured torestart in a case that cancellation of the uplink data transmissionbased on the uplink grant using the second DCI format is detected.

In an aspect of the present disclosure, in a case that cancellation ofthe uplink data transmission based on the uplink grant using the secondDCI format is detected, the uplink data transmission is performed basedon a transmission timing included in the second DCI format and atransmission parameter included in the first DCI format.

In an aspect of the present disclosure, in a case that cancellation ofthe uplink data transmission based on the uplink grant using the secondDCI format is detected, the uplink data transmission is performed basedon a transmission timing and a modulation and coding scheme (MCS), and afrequency domain resource assignment included in the second DCI format,and a transmission parameter that is not included in the second DCIformat, but included in the first DCI format.

In an aspect of the present disclosure, in a case of cancellation of theuplink data transmission based on the uplink grant using the second DCIformat is detected, an uplink grant for reallocation is detected basedon a notification timing for the uplink grant included in the second DCIformat.

Advantageous Effects

According to one or more aspects of the present disclosure, an efficientuplink data transmission can be achieved.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram illustrating an example of a communication systemaccording to a first implementation.

FIG. 2 is a diagram illustrating an example of a radio frame structurefor the communication system according to the first implementation.

FIG. 3 is a schematic block diagram illustrating a configuration of abase station apparatus 10 according to the first implementation.

FIG. 4 is a diagram illustrating an example of a signal detection unitaccording to the first implementation.

FIG. 5 is a schematic block diagram illustrating a configuration of aterminal apparatus 20 according to the first implementation.

FIG. 6 is a diagram illustrating an example of the signal detection unitaccording to the first implementation.

FIG. 7 is a diagram illustrating an example of a known uplink datatransmission.

FIG. 8 is a diagram illustrating an example of a stop of uplink datatransmission according to the first implementation.

FIG. 9 is a diagram illustrating an example of a stop of uplink datatransmission according to the first implementation.

FIG. 10 is a diagram illustrating an example of an uplink datatransmission according to the first implementation.

FIG. 11 is a diagram illustrating an example of an uplink dataretransmission according to the first implementation.

FIG. 12 is a diagram illustrating an example of a stop of uplink datatransmission according to the first implementation.

FIG. 13 is a diagram illustrating an example of an uplink datatransmission according to a second implementation.

FIG. 14 is a diagram illustrating an example of an uplink datatransmission according to a third implementation.

DESCRIPTION

A communication system according to the present implementations includesa base station apparatus (also referred to as a cell, a small cell, apico cell, a serving cell, a component carrier, an eNodeB (eNB), a HomeeNodeB, a Low Power Node, a Remote Radio Head, a gNodeB (gNB), a controlstation, a Bandwidth Part (BWP), or a Supplementary Uplink (SUL)), and aterminal apparatus (also referred to as a terminal, a mobile terminal, amobile station, or User Equipment (UE)). In the communication system, incase of a downlink, the base station apparatus serves as a transmittingapparatus (a transmission point, a transmit antenna group, or a transmitantenna port group), and the terminal apparatus serves as a receivingapparatus (a reception point, a reception terminal, a receive antennagroup, or a receive antenna port group). In a case of an uplink, thebase station apparatus serves as a receiving apparatus, and the terminalapparatus serves as a transmitting apparatus. The communication systemis also applicable to Device-to-Device (D2D) communication. In thiscase, the terminal apparatus serves both as a transmitting apparatus andas a receiving apparatus.

The communication system is not limited to data communication betweenthe terminal apparatus and the base station apparatus, the communicationinvolving human beings, but is also applicable to a form of datacommunication requiring no human intervention, such as Machine TypeCommunication (MTC), Machine-to-Machine (M2M) Communication,communication for Internet of Things (IoT), or Narrow Band-IoT (NB-IoT)(hereinafter referred to as MTC). In this case, the terminal apparatusserves as an MTC terminal. The communication system can use, in theuplink and the downlink, a multi-carrier transmission scheme such asDiscrete Fourier Transform Spread-Orthogonal Frequency DivisionMultiplexing (DFTS-OFDM, also referred to as Single Carrier-FrequencyDivision Multiple Access (SC-FDMA)) and Cyclic Prefix-OrthogonalFrequency Division Multiplexing (CP-OFDM). The communication system canalso use Filter Bank Multi Carrier (FBMC), Filtered-OFDM (f-OFDM) towhich a filter is applied, Universal Filtered-OFDM (UF-OFDM), orWindowing-OFDM (W-OFDM), a transmission scheme using a sparse code(Sparse Code Multiple Access (SCMA)), or the like. Furthermore, thecommunication system may apply DFT precoding and use a signal waveformfor which the filter described above is used. Furthermore, thecommunication system may apply code spreading, interleaving, the sparsecode, and the like in the above-described transmission scheme. It'snoted that, in the description below, at least one of the DFTS-OFDMtransmission and the CP-OFDM transmission is used in the uplink, whereasthe CP-OFDM transmission is used in the downlink, but that the presentimplementations are not limited to this configuration and any othertransmission scheme is applicable.

The base station apparatus and the terminal apparatus according to thepresent implementations can communicate in a frequency band for which anapproval of use (license) has been obtained from the government of acountry or region where a radio operator provides services, that is, aso-called licensed band, and/or in a frequency band for which noapproval (license) from the government of the country or region isrequired, that is, a so-called unlicensed band. In the unlicensed band,communication may be based on carrier sense (e.g., a listen before talkscheme).

According to the present implementations, “X/Y” includes the meaning of“X or Y”. According to the present implementations, “X/Y” includes themeaning of “X and Y”. According to the present implementations, “X/Y”includes the meaning of “X and/or Y”.

First Implementation

FIG. 1 is a diagram illustrating an example of a configuration of acommunication system according to the present implementation. Thecommunication system according to the present implementation includes abase station apparatus 10 and terminal apparatuses 20-1 to 20-n 1 (n1 isa number of terminal apparatuses connected to the base station apparatus10). The terminal apparatuses 20-1 and 20-n 1 are also collectivelyreferred to as terminal apparatuses 20. Coverage 10 a is a range (acommunication area) in which the base station apparatus 10 can connectto the terminal apparatus 20 (coverage 10 a is also referred to as acell).

In FIG. 1, radio communication of an uplink r30 includes at least thefollowing uplink physical channels. The uplink physical channels areused for transmitting information output from a higher layer.

-   -   Physical Uplink Control Channel (PUCCH)    -   Physical Uplink Shared Channel (PUSCH)    -   Physical Random Access Channel (PRACH)

The PUCCH is a physical channel that is used to transmit Uplink ControlInformation (UCI). The uplink control information includes a positiveacknowledgement (ACK)/Negative acknowledgement (NACK) in response todownlink data (a Downlink transport block, a Medium Access ControlProtocol Data Unit (MAC PDU), a Downlink-Shared Channel (DL-SCH), and aPhysical Downlink Shared Channel (PDSCH). The ACK/NACK is also referredto as a Hybrid Automatic Repeat request ACKnowledgement (HARQ-ACK), aHARQ feedback, a HARQ response, or a signal indicating HARQ controlinformation or a delivery confirmation.

The uplink control information includes a Scheduling Request (SR) usedto request a PUSCH (Uplink-Shared Channel (UL-SCH)) resource for initialtransmission. The scheduling request includes a positive schedulingrequest or a negative scheduling request. The positive schedulingrequest indicates that a UL-SCH resource for initial transmission isrequested. The negative scheduling request indicates that the UL-SCHresource for the initial transmission is not requested.

The uplink control information includes downlink Channel StateInformation (CSI). The downlink channel state information includes aRank Indicator (RI) indicating a preferable spatial multiplexing order(the number of layers), a Precoding Matrix Indicator (PMI) indicating apreferable precoder, a Channel Quality Indicator (CQI) designating apreferable transmission rate, and the like. The PMI indicates a codebookdetermined by the terminal apparatus. The codebook is related toprecoding of the physical downlink shared channel. The CQI can use anindex (CQI index) indicative of a preferable modulation scheme (forexample, QPSK, 16QAM, 64QAM, 256QAM, or the like), a preferable codingrate, and a preferable frequency utilization efficiency in a prescribedband. The terminal apparatus selects, from the CQI table, a CQI indexconsidered to allow a transport block on the PDSCH to be received withina prescribed block error probability (for example, an error rate of0.1). Here, the terminal apparatus may have multiple prescribed errorprobabilities (error rates) for transport blocks. For example, an errorrate for eMBB data may be targeted at 0.1 and an error rate for URLLCmay be targeted 0.00001. The terminal apparatus may perform CSI feedbackfor each target error rate (transport block error rate) configured bythe higher layer (e.g., setup through RRC signaling from the basestation), or may perform CSI feedback for a target error rate ofmultiple target error rates configured by the higher layer. It's notedthat the CSI may be calculated using an error rate not for eMBB (e.g.0.1) on the basis of not whether or not the error rate is configuredthrough RRC signaling but whether or not a CQI table not for eMBB (thatis, transmissions where the BLER does not exceed 0.1) is selected.

PUCCH formats 0 to 4 are defined for the PUCCH, and PUCCH formats 0 and2 are transmitted in 1 to 2 OFDM symbols and PUCCH formats 1, 3, and 4are transmitted in 4 to 14 OFDM symbols. PUCCH formats 0 and 1 are usedfor up to 2-bit notification, and can notify only the HARQ-ACK, only theSR, or simultaneously the HARQ-ACK and the SR. PUCCH formats 1, 3, and 4are used for notification of bits the number of which is larger thantwo, and can simultaneously notify the HARQ-ACK, the SR, and the CSI.The number of OFDM symbols used for PUCCH transmission is configured bya higher layer (e.g., setup through RRC signaling), and the use of anyPUCCH format depends on whether there is SR transmission or CSItransmission at the timing at which the PUCCH is transmitted (slot, OFDMsymbol).

The PUSCH is a physical channel that is used to transmit uplink data(Uplink Transport Block, Uplink-Shared Channel (UL-SCH)). The PUSCH maybe used to transmit the HARQ-ACK in response to the downlink data and/orthe channel state information along with the uplink data. The PUSCH maybe used to transmit only the channel state information. The PUSCH may beused to transmit only the HARQ-ACK and the channel state information.

The PUSCH is used to transmit radio resource control (Radio ResourceControl (RRC)) signaling. The RRC signaling is also referred to as anRRC message/RRC layer information/RRC layer signaling/an RRC layerparameter/RRC information/an RRC information element. The RRC signalingis information/signal processed in a radio resource control layer. TheRRC signaling transmitted from the base station apparatus may besignaling common to multiple terminal apparatuses in a cell. The RRCsignaling transmitted from the base station apparatus may be signalingdedicated to a certain terminal apparatus (also referred to as dedicatedsignaling). In other words, user equipment-specific (UE-specific)information may be transmitted through signaling dedicated to thecertain terminal apparatus. The RRC message can include a UE Capabilityof the terminal apparatus. The UE Capability is information indicating afunction supported by the terminal apparatus.

The PUSCH is used to transmit a Medium Access Control Element (MAC CE).The MAC CE is information/signal processed (transmitted) in a MediumAccess Control layer. For example, a Power Headroom (PH) may be includedin the MAC CE and may be reported via the physical uplink sharedchannel. In other words, a MAC CE field is used to indicate a level ofthe power headroom. The uplink data can include the RRC message and theMAC CE. The RRC signaling and/or the MAC CE is also referred to as ahigher layer signal (higher layer signaling). The RRC signaling and/orthe MAC CE are included in a transport block.

The PUSCH may be used for data transmission of dynamic scheduling forperforming uplink data transmission on a specified radio resource(allocation of an aperiodic radio resource), based on uplinktransmission parameters (e.g., time-domain resource allocation,frequency-domain resource allocation, and the like) included in the DCIformat. The PUSCH may be used for data transmission based onSemi-Persistent scheduling (SPS) Type 2 (Configured uplink grant type 2)by which data transmission using a periodic radio resource is granted,by, through the RRC, receiving the TransformPrecoder (precoder),nrofHARQ (the number of HARQ processes), and repK-RV (a redundancyversion pattern in repetitive transmission of the same data), andthereafter, receiving DCI format 0_0/0_1 with CRC scrambled with aCS-RNTI, and further receiving activation control information with thereceived DCI format 0_0/0_1 having a prescribed field configured withValidation. Here, all bits for a HARQ process number, 2 bits for a RV,and the like may be used as a field used for the Validation.Furthermore, all bits of a HARQ process number, all bits of an MCS, allbits of a resource block assignment, 2 bits of a RV, and the like may beused as a field used for Validation of deactivation (release) controlinformation for a type 2 configured grant transmission. The PUSCH may befurther used for a type 1 configured grant transmission by which aperiodic data transmission is granted by, through the RRC, receivingrrcConfiguredUplinkGrant in addition to the information of the type 2configured grant transmission. The rrcConfiguredUplinkGrant informationmay include the time-domain resource allocation, a time-domain offset,the frequency-domain resource allocation, a DMRS configuration, and thenumber of repetitive transmissions of the same data (repK). In a casethat the type 1 configured grant transmission and the type 2 configuredgrant transmission are configured in the same serving cell (in thecomponent carrier), the type 1 configured grant transmission may beprioritized. In a case that an uplink grant for the type 1 configuredgrant transmission and an uplink grant for the dynamic schedulingoverlap in the time domain in the same serving cell, the uplink grantfor the dynamic scheduling may override (that is, the dynamic schedulingonly is used and the uplink grant for the type 1 configured granttransmission is reversed). The multiple uplink grants overlapping in thetime domain may refer to at least some of the OFDM symbols overlapping,or portions of the times in the OFDM symbols overlapping because an OFDMsymbol length differs in a case that a subcarrier spacing (SCS) isdifferent. The configuration of the type1 configured grant transmissioncan also be configured for the Scell that has not been activated throughthe RRC, and the uplink grant for the type1 configured granttransmission may be validated after the Scell configured with the type1configured grant transmission is activated.

The PRACH is used to transmit a preamble used for random access. ThePRACH is used for indicating the initial connection establishmentprocedure, the handover procedure, the connection re-establishmentprocedure, synchronization (timing adjustment) for uplink transmission,and the request for the PUSCH (UL-SCH) resource.

In the uplink radio communication, an Uplink Reference Signal (UL RS) isused as an uplink physical signal. The uplink reference signal includesa Demodulation Reference Signal (DMRS) and a Sounding Reference Signal(SRS). The DMRS is associated with transmission of the physicaluplink-shared channel/physical uplink control channel. For example, thebase station apparatus 10 uses the demodulation reference signal toperform channel estimation/channel compensation in a case ofdemodulating the physical uplink-shared channel/the physical uplinkcontrol channel. For an uplink DMRS, the maximum number of OFDM symbolsfor front-loaded DMRS and a configuration for the DMRS symbol addition(DMRS-add-pos) are specified by the base station apparatus through theRRC. In a case that the front-loaded DMRS is in 1 OFDM symbol (singlesymbol DMRS), a frequency domain location, cyclic shift values in thefrequency domain, and how different frequency domain locations are usedin the OFDM symbol including the DMRS are specified in the DCI, and in acase that the front-loaded DMRS is in 2 OFDM symbols (double symbolDMRS), a configuration for a time spread of a length 2 is specified inthe DCI in addition to the above.

The Sounding Reference Signal (SRS) is not associated with thetransmission of the physical uplink shared channel/physical uplinkcontrol channel. In other words, with or without uplink datatransmission, the terminal apparatus transmits periodically oraperiodically the SRS. In the periodic SRS, the terminal apparatustransmits the SRS based on parameters notified through signaling (e.g.,RRC) from a layer higher than the base station apparatus. On the otherhand, in the aperiodic SRS, the terminal apparatus transmits the SRSbased on parameters notified through signaling (e.g., RRC) from a layerhigher than the base station apparatus and a physical downlink controlchannel (for example, DCI) indicating a transmission timing of the SRS.The base station apparatus 10 uses the SRS to measure an uplink channelstate (CSI Measurement). The base station apparatus 10 may performtiming alignment and closed loop transmission power control frommeasurement results obtained by receiving the SRS.

In FIG. 1, at least the following downlink physical channels are used inradio communication of the downlink r31. The downlink physical channelsare used for transmitting information output from the higher layer.

-   -   Physical Broadcast Channel (PBCH)    -   Physical Downlink Control Channel (PDCCH)    -   Physical Downlink Shared Channel (PDSCH)

The PBCH is used for broadcasting a Master Information Block (MIB, aBroadcast Channel (BCH)) that is used commonly by the terminalapparatuses. The MIB is one of pieces of system information. Forexample, the MIB includes a downlink transmission bandwidthconfiguration and a System Frame number (SFN). The MIB may includeinformation indicating at least some of numbers of a slot, a subframe,and a radio frame in which a PBCH is transmitted.

The PDCCH is used to transmit Downlink Control Information (DCI). Forthe downlink control information, multiple formats based on applications(also referred to as DCI formats) are defined. The DCI format may bedefined based on the type and the number of bits of the DCI constitutinga single DCI format. The downlink control information includes controlinformation for downlink data transmission and control information foruplink data transmission. The DCI format for downlink data transmissionis also referred to as downlink assignment (or downlink grant, DLGrant). The DCI format for uplink data transmission is also referred toas uplink grant (or uplink assignment, UL Grant).

The DCI format for downlink data transmission includes DCI format 1_0,DCI format 1_1, and the like. DCI format 1_0 is for fallback downlinkdata transmission, and has configurable parameters (fields) fewer thanDCI format 1_1 supporting MIMO and the like. DCI format 1_1 is capableof changing the presence or absence (valid/invalid) of the parameter(field) to be notified, and has the number of bits larger than that ofDCI format 1_0 depending on the field to be valid. On the other hand,DCI format 1_1 is capable of notifying MIMO or multiple codewordstransmission, ZP CSI-RS trigger, CBG transmission information, and thelike, and a presence or absence, or the number of bits of some fieldsthereof are added in accordance with the configuration by the higherlayer (e.g., RRC signaling, MAC CE). A single downlink assignment isused for scheduling a single PDSCH in a single serving cell. Thedownlink grant may be used for at least scheduling a PDSCH within thesame slot/subframe as the slot/subframe in which the downlink grant hasbeen transmitted. The downlink grant may be used for scheduling a PDSCHin a slot/subframe after K₀ slots/subframes from the slot/subframe inwhich the downlink grant has been transmitted. The downlink grant may beused for scheduling a PDSCH in multiple slots/subframes. The downlinkassignment in DCI format 1_0 includes the following fields. For example,the relevant fields include a DCI format identifier, a frequency domainresource assignment (resource block allocation for the PDSCH, resourceallocation), a time domain resource assignment, VRB to PRB mapping, aModulation and Coding Scheme (MCS) for the PDSCH (information indicatinga modulation order and a coding rate), a NEW Data Indicator (NDI)indicating an initial transmission or retransmission, information forindicating the HARQ process number in the downlink, a Redundancy version(RV) indicating information on redundant bits added to the codewordduring error correction coding, Downlink Assignment Index (DAI), aTransmission Power Control (TPC) command for the PUCCH, a resourceindicator for the PUCCH, an indicator for HARQ feedback timing from thePDSCH, and the like. It's noted that the DCI format for each downlinkdata transmission includes information (fields) required for theapplication among the above-described information. Either or both of DCIformat 1_0 and DCI format 1_1 may be used for activation anddeactivation (release) of the downlink SPS.

The DCI format for uplink data transmission includes DCI format 0_0, DCIformat 0_1, and the like. DCI format 0_0 is for fallback uplink datatransmission, and has configurable parameters (fields) fewer than DCIformat 0_1 supporting MIMO and the like. DCI format 0_1 is capable ofchanging the presence or absence (valid/invalid) of the parameter(field) to be notified, and has the number of bits larger than that ofDCI format 0_0 depending on the field to be valid. On the other hand,DCI format 0_1 is capable of notifying MIMO or multiple codewordstransmission, a SRS resource indicator, precoding information, antennaport information, SRS request information, CSI request information, CBGtransmission information, uplink PTRS association, DMRS sequenceinitialization, and the like, and a presence or absence, or the numberof bits of some fields thereof are added in accordance with theconfiguration by the higher layer (e.g., RRC signaling). A single uplinkgrant is used for notifying the terminal apparatus of scheduling of asingle PUSCH in a single serving cell. The uplink grant may be used forscheduling a PUSCH in a slot/subframe after K₂ slots/subframes from theslot/subframe in which the uplink grant has been transmitted. Thedownlink grant may be used for scheduling a PUSCH in multipleslots/subframes. The uplink grant in DCI format 0_0 includes thefollowing fields. For example, the relevant fields include a DCI formatidentifier, a frequency domain resource assignment (information onresource block allocation for transmitting the PUSCH and a time domainresource assignment, a frequency hopping flag, information on the MCSfor the PUSCH, RV, NDI, information indicating the HARQ process numberin the uplink, a TPC command for the PUSCH, a Supplemental UL (UL/SUL)indicator, and the like. Either or both of DCI format 0_0 and DCI format0_1 may be used for activation and deactivation (release) of the uplinkSPS.

The DCI format may be used in DCI format 2_0 with CRC scrambled with anSFI-RNTI for notification of a slot format indicator (SFI). The DCIformat may be used in DCI format 2_1 with CRC scrambled with an INT-RNTIfor notification of a PRB (one or more) and an OFDM symbol (one or more)that the terminal apparatus may assume no downlink data transmissionintended for the terminal apparatus itself. The DCI format may be usedin DCI format 2_2 with CRC scrambled with a TPC-PUSCH-RNTI or aTPC-PUCCH-RNTI for TPC command transmission for the PUSCH and the PUCCH.The DCI format may be used in DCI format 2_3 with CRC scrambled with aTPC-SRS-RNTI for TPC command group transmission for SRS transmission byone or terminal apparatuses. DCI format 2_3 may also be used for the SRSrequest. The DCI format may be used in DCI format 2_X (for example, DCIformat 2_4, DCI format 2_1A) with CRC scrambled with an INT-RNTI oranother RNTI (e.g., UL-INT-RNTI) for notification of a PRB (one or more)and an OFDM symbol (one or more), among those already scheduled by ULGrant/Configured UL Grant, in which the terminal apparatus does nottransmit data.

For the MCS for the PDSCH/PUSCH, an index (MCS index) indicating amodulation order and target coding rate for the PDSCH/the PUSCH can beused. The modulation order is associated with a modulation scheme. Themodulation orders “2”, “4”, and “6” indicate “QPSK,” “16QAM,” and“64QAM,” respectively. Furthermore, in a case that 256QAM and 1024QAMare configured by the higher layer (e.g., RRC signaling), the modulationorders “8” and “10” can be notified, and indicate “256QAM” and“1024QAM”, respectively. The target coding rate is used to determine atransport block size (TBS) that is the number of bits to be transmitted,depending on the number of resource elements (the number of resourceblocks) of the PDSCH/PUSCH scheduled in the PDCCH. A communicationsystem 1 (the base station apparatus 10 and the terminal apparatus 20)shares a method of calculating the transport block size by the MCS, thetarget coding rate, and the number of resource elements (the number ofresource blocks) allocated for the PDSCH/PUSCH transmission.

The PDCCH is generated by adding a Cyclic Redundancy Check (CRC) to thedownlink control information. In the PDCCH, CRC parity bits arescrambled with a prescribed identifier (also referred to as an exclusiveOR operation, mask). The parity bits are scrambled with a Cell-RadioNetwork Temporary Identifier (C-RNTI), a Configured Scheduling(CS)-RNTI, a Temporary C (TC)-RNTI, a Paging (P)-RNTI, a SystemInformation (SI)-RNTI, a Random Access (RA)-RNTI, or with an INT-RNTI, aSlot Format Indicator (SFI)-RNTI, a TPC-PUSCH-RNTI, a TPC-PUCCH-RNTI, ora TPC-SRS-RNTI. The C-RNTI and the CS-RNTI are identifiers foridentifying the terminal apparatus in a cell by the dynamic schedulingand the SPS/grant free access, respectively. The Temporary C-RNTI is anidentifier for identifying the terminal apparatus that has transmitted arandom access preamble in a contention based random access procedure.The C-RNTI and the Temporary C-RNTI are used to control PDSCHtransmission or PUSCH transmission in a single subframe. The CS-RNTI isused to periodically allocate a resource for the PDSCH or the PUSCH. TheP-RNTI is used to transmit a paging message (Paging Channel (PCH)). TheSI-RNTI is used to transmit the SIB, and the RA-RNTI is used to transmita random access response (message 2 in a random access procedure). TheSFI-RNTI is used to notify a slot format. The INT-RNTI is used to notifya downlink or uplink Pre-emption. The TPC-PUSCH-RNTI and theTPC-PUCCH-RNTI, and the TPC-SRS-RNTI are used to notify transmissionpower control values of the PUSCH and the PUCCH, and the SRS,respectively. It's noted that the identifier may include a CS-RNTI foreach configuration in order to configure multiple grant freeaccesses/SPSs. The DCI to which the CRC scrambled with the CS-RNTI isadded can be used for activation, deactivation (release), parameterchange, or retransmission control (ACK/NACK transmission) of the grantfree access, and the parameter may include a resource configuration (aconfiguration parameter for a DMRS, a resource in a frequency domain anda time domain of the grant free access, an MCS used for the grant freeaccess, the number of repetitions, with or without applying a frequencyhopping, and the like).

The PDSCH is used to transmit the downlink data (the downlink transportblock, DL-SCH). The PDSCH is used to transmit a system informationmessage (also referred to as a System Information Block (SIB)). Some orall of the SIBs can be included in the RRC message.

The PDSCH is used to transmit the RRC signaling. The RRC signalingtransmitted from the base station apparatus may be common to themultiple terminal apparatuses in the cell (unique to the cell). That is,the information common to the user equipments in the cell is transmittedusing RRC signaling unique to the cell. The RRC signaling transmittedfrom the base station apparatus may be a message dedicated to a certainterminal apparatus (also referred to as dedicated signaling). In otherwords, user equipment-specific (UE-Specific) information may betransmitted using a message dedicated to the certain terminal apparatus.

The PDSCH is used to transmit the MAC CE. The RRC signaling and/or theMAC CE is also referred to as a higher layer signal (higher layersignaling). The PMCH is used to transmit multicast data (MulticastChannel (MCH)).

In the downlink radio communication in FIG. 1, a Synchronization signal(SS) and a Downlink Reference Signal (DL RS) are used as downlinkphysical signals.

The synchronization signal is used for the terminal apparatus to takesynchronization in the frequency domain and the time domain in thedownlink. The downlink reference signal is used for the terminalapparatus to perform the channel estimation/channel compensation on thedownlink physical channel. For example, the downlink reference signal isused to demodulate the PBCH, the PDSCH, and the PDCCH. The downlinkreference signal can be used for the terminal apparatus to measure thedownlink channel state (CSI measurement). The downlink reference signalmay include a Cell-specific Reference Signal (CRS), a Channel stateinformation Reference Signal (CSI-RS), a Discovery Reference Signal(DRS), and a Demodulation Reference Signal (DMRS).

The downlink physical channel and the downlink physical signal are alsocollectively referred to as a downlink signal. The uplink physicalchannel and the uplink physical signal are also collectively referred toas an uplink signal. The downlink physical channel and the uplinkphysical channel are also collectively referred to as a physicalchannel. The downlink physical signal and the uplink physical signal arealso collectively referred to as a physical signal.

The BCH, the UL-SCH, and the DL-SCH are transport channels. Channelsused in the Medium Access Control (MAC) layer are referred to astransport channels. A unit of the transport channel used in the MAClayer is also referred to as a Transport Block (TB) or a MAC ProtocolData Unit (PDU). The transport block is a unit of data that the MAClayer delivers to the physical layer. In the physical layer, thetransport block is mapped to a codeword, and coding processing and thelike are performed for each codeword.

In higher layer processing, processing is performed on a layer higherthan the physical layer, such as a Medium Access Control (MAC) layer, aPacket Data Convergence Protocol (PDCP) layer, a Radio Link Control(RLC) layer, and a Radio Resource Control (RRC) layer.

Processing is performed on a layer higher than the physical layer, suchas a Medium Access Control (MAC) layer, a Packet Data ConvergenceProtocol (PDCP) layer, a Radio Link Control (RLC) layer, and a RadioResource Control (RRC) layer.

A higher layer processing unit configures various RNTIs for eachterminal apparatus. The RNTI is used for encryption (scrambling) of thePDCCH, the PDSCH, and the like. In the higher layer processing, thedownlink data (transport block, DL-SCH) allocated to the PDSCH, thesystem information specific to the terminal apparatus (SystemInformation Block: SIB), the RRC message, the MAC CE, and the like aregenerated or acquired from the higher node and output. In the higherlayer processing, various kinds of configuration information of theterminal apparatus 20 are managed. It's noted that a part of thefunction of the radio resource control may be performed in the MAC layeror the physical layer.

In the higher layer processing, information on the terminal apparatus,such as the function supported by the terminal apparatus (UEcapability), is received from the terminal apparatus 20. The terminalapparatus 20 transmits its own function to the base station apparatus 10by a higher layer signaling (RRC signaling). The information on theterminal apparatus includes information for indicating whether theterminal apparatus supports a prescribed function or information forindicating that the terminal apparatus has completed introduction andtesting of the prescribed function. The information for indicatingwhether the prescribed function is supported includes information forindicating whether the introduction and testing of the prescribedfunction have been completed.

In a case that the terminal apparatus supports the prescribed function,the terminal apparatus transmits information (parameters) for indicatingwhether the prescribed function is supported. In a case that theterminal apparatus does not support a prescribed function, the terminalapparatus may not transmit information (parameters) for indicatingwhether the prescribed function is supported. In other words, whetherthe prescribed function is supported is notified by whether information(parameters) for indicating whether the prescribed function is supportedis transmitted. The information (parameters) for indicating whether theprescribed function is supported may be notified by using one bit of 1or 0.

In FIG. 1, the base station apparatus 10 and the terminal apparatuses 20support, in the uplink, Multiple Access (MA) using the grant free access(also referred to grant free access, grant less access, Contention-basedaccess, Autonomous access, Resource allocation for uplink transmissionwithout grant, type 1 configured grant transmission, or the like, andhereinafter referred to as grant free access). The grant free access isa scheme in which the terminal apparatus transmits uplink data (such asa physical uplink channel) without performing a procedure to transmit aSR by the terminal apparatus and specifies a physical resource andtransmission timing of data transmission by way of a UL Grant using theDCI by the base station apparatus (also referred to as UL Grant throughL1 signaling). Thus, in addition to an allocation periodicity foravailable resources, a target received power, a value (a) of fractionalTPC, the number of HARQ processes, and a RV pattern during repetitivetransmission of the same transport, the terminal apparatus can receive,in advance through RRC signaling (SPS-config), a physical resource(resource assignment in the frequency domain, resource assignment in thetime domain) that can be used for grant free access and a transmissionparameter (that may include a cyclic shift or OCC of DMRS, an antennaport number, a position or the number of OFDM symbols in which DMRS isallocated, the number of repetitive transmissions of the same transport,and the like), as Configured Uplink Grant (rrcConfiguredUplinkGrant,configured uplink grant) in RRC signaling, and perform data transmissionusing the configured physical resource only in a case that thetransmission data is in the buffer. In other words, in a case that thehigher layer does not deliver transport blocks to transmit in the grantfree access, data transmission in the grant free access is notperformed. In a case that the terminal apparatus receives SPS-config,but does not receive Configured Uplink Grant through RRC signaling, theterminal apparatus can also perform similar data transmission in the SPS(type2 configured grant transmission) by SPS activation via the ULGrant.

There are following two types of grant free access. A first type is type1 configured grant transmission (UL-TWG-type 1), that is a scheme inwhich the base station apparatus transmits transmission parameters forthe grant free access to the terminal apparatus through higher layersignaling (e.g., RRC), and transmits start of grant (activation, RRCsetup) and end of grant (deactivation (release), RRC release) of thedata transmission in the grant free access, and change of thetransmission parameters also through higher layer signaling. Here, thetransmission parameters for the grant free access may include a physicalresource (time domain and frequency domain resource assignment) that canbe used for data transmission in the grant free access, a periodicity ofthe physical resource, an MCS, with or without applying repetitivetransmission, the number of repetitions, an RV configuration forrepetitive transmission, with or without applying a frequency hopping, ahopping pattern, a DMRS configuration (the number of OFDM symbols forfront-loaded DMRS, configurations of cyclic shift and time spread, orthe like), the number of HARQ processes, information on transformerprecoder, and information on a configuration for TPC. The transmissionparameters and the start of grant of the data transmission related tothe grant free access may be simultaneously configured, or the start ofgrant of the data transmission in the grant free access may beconfigured at different timings (in a case of a SCell, SCell activation,and the like) after the transmission parameters for the grant freeaccess are configured. A second type is type 2 configured granttransmission (UL-TWG-type2), in which the base station apparatustransmits transmission parameters for the grant free access to theterminal apparatus through higher layer signaling (e.g., RRC), andtransmits start of grant (activation) and end of grant (deactivation(release)) of the data transmission in the grant free access, and changeof the transmission parameters using the DCI (L1 signaling). Here, aperiodicity of the physical resource in RRC, the number of repetitions,an RV configuration for repetitive transmission, the number of HARQprocesses, information on transformer precoder, and information on aconfiguration for TPC may be included, and the start of grant(activation) on the basis of the DCI may include a physical resource(resource block allocation) that can be used for the grant free access.The transmission parameters and the start of grant of the datatransmission related to the grant free access may be simultaneouslyconfigured, or the start of grant of the data transmission in the grantfree access may be configured at different timings after thetransmission parameters for the grant free access are configured. Anaspect of the present disclosure may be applied to any grant free accessdescribed above.

On the other hand, Semi-Persistent Scheduling (SPS) technology isintroduced in LTE, and periodic resource allocation is possible mainlyin Voice over Internet Protocol (VoIP) applications. In the SPS, the DCIis used to perform start of grant (activation) by way of an UL Grantincluding the transmission parameters such as a physical resourcedesignation (resource blocks allocation) and an MCS. Thus, the type(UL-TWG-type 1) performing the start of grant (activation) in the grantfree access through higher layer signaling (e.g., RRC) differ from theSPS in the starting procedure. The UL-TWG-type 2 is the same in thepoint of performing the start of grant (activation) using the DCI (L1signaling), but may be different in the point of being capable of beingused in the SCell, the BWP, and the SUL, or of notifying the number ofrepetitions, and an RV configuration for repetitive transmission throughRRC signaling. The base station apparatus may perform scrambling withdifferent types of RNTI for the DCI (L1 signaling) used for the grantfree access (UL-TWG-type 1 and UL-TWG-type 2) and the DCI used for thedynamic scheduling, or may perform scrambling with the same RNTI betweenthe DCI used for the re-transmission control of the UL-TWG-type 1 andthe DCI used for the activation and deactivation (release) and there-transmission control of the UL-TWG-type 2.

The base station apparatus 10 and the terminal apparatuses 20 maysupport non-orthogonal multiple access in addition to orthogonalmultiple access. It's noted that the base station apparatus 10 and theterminal apparatuses 20 can support both the grant free access and thescheduled access (dynamic scheduling). Here, an “uplink scheduledaccess” refers to data transmission by the terminal apparatus 20according to the following procedure. The terminal apparatus 20 requestsa radio resource for transmitting uplink data to the base stationapparatus 10 using the random access procedure (Random Access Procedure)or the SR. The base station apparatus provides an UL Grant to eachterminal apparatus based on the RACH or the SR by way of the DCI. In acase that the terminal apparatus receives an UL Grant as the controlinformation from the base station apparatus, the terminal apparatustransmits uplink data using a prescribed radio resource, based on anuplink transmission parameter included in the UL Grant.

The downlink control information for physical channel transmission inthe uplink may include a shared field shared between the scheduledaccess and the grant free access. In this case, in a case that the basestation apparatus 10 indicates transmission of the uplink physicalchannel using the grant free access, the base station apparatus 10 andthe terminal apparatus 20 interpret a bit sequence stored in the sharedfield in accordance with a configuration for the grant free access(e.g., a look-up table defined for the grant free access). Similarly, ina case that the base station apparatus 10 indicates transmission of theuplink physical channel using the scheduled access, the base stationapparatus 10 and the terminal apparatus 20 interpret the shared field inaccordance with a configuration for the scheduled access. Transmissionof the uplink physical channel in the grant free access is referred toas Asynchronous data transmission. It's noted that the transmission ofthe uplink physical channel in the scheduled is referred to asSynchronous data transmission.

In the grant free access, the terminal apparatus 20 may randomly selecta radio resource for transmission of uplink data. For example, theterminal apparatus 20 has been notified, by the base station apparatus10, of multiple candidates for available radio resources as a resourcepool, and randomly selects a radio resource from the resource pool. Inthe grant free access, the radio resource in which the terminalapparatus 20 transmits the uplink data may be configured in advance bythe base station apparatus 10. In this case, the terminal apparatus 20transmits the uplink data using the radio resource configured in advancewithout receiving the UL Grant (including a physical resourcedesignation) in the DCI. The radio resource includes multiple uplinkmultiple access resources (resources to which the uplink data can bemapped). The terminal apparatus 20 transmits the uplink data by usingone or more uplink multiple access resources selected from the multipleuplink multiple access resources. It's noted that the radio resource inwhich the terminal apparatus 20 transmits the uplink data may bepredetermined in the communication system including the base stationapparatus 10 and the terminal apparatus 20. The radio resource fortransmission of the uplink data may be notified to the terminalapparatus 20 by the base station apparatus 10 using a physical broadcastchannel (e.g., Physical Broadcast Channel (PBCH)/Radio Resource Control(RRC)/system information (e.g. System Information Block (SIB)/physicaldownlink control channel (downlink control information, e.g., PhysicalDownlink Control Channel (PDCCH), Enhanced PDCCH (EPDCCH), MTC PDCCH(MPDCCH), and Narrowband PDCCH (NPDCCH)).

In the grant free access, the uplink multiple access resource includes amultiple access physical resource and a Multi-Access Signature Resource.The multiple access physical resource is a resource including time andfrequency. The multiple access physical resource and the multi-accesssignature resource may be used to identify the uplink physical channeltransmitted by each terminal apparatus. The resource blocks are units towhich the base station apparatus 10 and the terminal apparatus 20 arecapable of mapping the physical channel (e.g., the physical data sharedchannel or the physical control channel). Each of the resource blocksincludes one or more subcarriers (e.g., 12 subcarriers or 16subcarriers) in a frequency domain.

The multi-access signature resource includes at least one multi-accesssignature of multiple multi-access signature groups (also referred to asmulti-access signature pools). The multi-access signature is informationindicating a characteristic (mark or indicator) that distinguishes(identifies) the uplink physical channel transmitted by each terminalapparatus. Examples of the multi-access signature include a spatialmultiplexing pattern, a spreading code pattern (a Walsh code, anOrthogonal Cover Code (OCC), a cyclic shift for data spreading, thesparse code, or the like), an interleaved pattern, a demodulationreference signal pattern (a reference signal sequence, the cyclic shift,the OCC, or IFDM)/an identification signal pattern, and transmit power,at least one of which is included in the multi-access signature. In thegrant free access, the terminal apparatus 20 transmits the uplink databy using one or more multi-access signatures selected from themulti-access signature pool. The terminal apparatus 20 can notify thebase station apparatus 10 of available multi-access signatures. The basestation apparatus 10 can notify the terminal apparatus of a multi-accesssignature used by the terminal apparatus 20 to transmit the uplink data.The base station apparatus 10 can notify the terminal apparatus 20 of anavailable multi-access signature group by the terminal apparatus 20 totransmit the uplink data. The available multi-access signature group maybe notified by using the broadcast channel/RRC/systeminformation/downlink control channel. In this case, the terminalapparatus 20 can transmit the uplink data by using a multi-accesssignature selected from the notified multi-access signature group.

The terminal apparatus 20 transmits the uplink data by using a multipleaccess resource. For example, the terminal apparatus 20 can map theuplink data to a multiple access resource including a multi-carriersignature resource including one multiple access physical resource, aspreading code pattern, and the like. The terminal apparatus 20 canallocate the uplink data to a multiple access resource including amulti-carrier signature resource including one multiple access physicalresource and an interleaved pattern. The terminal apparatus 20 can alsomap the uplink data to a multiple access resource including one multipleaccess physical resource and a multi-access signature resource includinga demodulation reference signal pattern/identification signal pattern.The terminal apparatus 20 can also map the uplink data to a multipleaccess resource including one multiple access physical resource and amulti-access signature resource including a transmit power pattern(e.g., the transmit power for each of the uplink data may be configuredto cause a difference in a received power at the base station apparatus10). In such grant free access, the communication system of the presentimplementation may allow the uplink data transmitted by the multipleterminal apparatuses 20 to overlap (be superimposed, spatiallymultiplexed, non-orthogonally multiplexed, collide) with one another andbe transmitted in the uplink multiple access physical resource.

The base station apparatus 10 detects, in the grant free access, asignal of the uplink data transmitted by each terminal apparatus. Todetect the uplink data signal, the base station apparatus 10 may includeSymbol Level Interference Cancellation (SLIC) in which interference iscanceled based on a demodulation result for an interference signal,Codeword Level Interference Cancellation (CWIC, also referred to asSequential Interference Canceler (SIC) or Parallel Interference Canceler(PIC)) in which interference is canceled based on the decoding resultfor the interference signal, turbo equalization, maximum likelihooddetection (MLD, Reduced complexity maximum likelihood detection (R-MLD))in which transmit signal candidates are searched for the most probablesignal, Enhanced Minimum Mean Square Error-Interference RejectionCombining (EMMSE-IRC) in which interference signals are suppressed bylinear computation, signal detection based on message passing (Beliefpropagation (BP), Matched Filter (MF)-BP in which a matched filter iscombined with BP, or the like.

FIG. 2 is a diagram illustrating an example of a radio frame structurefor a communication system according to the present implementation. Theradio frame structure indicates a configuration of multiple accessphysical resources in a time domain. One radio frame includes multipleslots (or may include subframes). FIG. 2 is an example in which oneradio frame includes 10 slots. The terminal apparatus 20 has asubcarrier spacing used as a reference (reference numerology). Thesubframe includes multiple OFDM symbols generated at the subcarrierspacings used as the reference. FIG. 2 is an example in which asubcarrier spacing is 15 kHz, one frame includes 10 slots, one subframeincludes one slot, and one slot includes 14 OFDM symbols. In a case thatthe subcarrier spacing is 15 kHz×2μ (μ is an integer of 0 or more), oneframe includes 2μ×10 slots and one subframe includes 2μ slots.

FIG. 2 illustrates a case where the subcarrier spacing used as thereference is the same as a subcarrier spacing used for the uplink datatransmission. The communication system according to the presentimplementation may use slots as minimum units to which the terminalapparatus 20 maps the physical channel (e.g., the physical data sharedchannel or the physical control channel). In this case, in the multipleaccess physical resource, one slot is defined as a resource block unitin the time domain. Furthermore, in the communication system accordingto the present implementation, a minimum unit for mapping the physicalchannel by the terminal apparatus 20 may be one or multiple OFDM symbols(e.g., 2 to 13 OFDM symbols). The base station apparatus 10 has one ormultiple OFDM symbols serving as a resource block unit in the timedomain. The base station apparatus 10 may signal a minimum unit formapping a physical channel to the terminal apparatus 20.

FIG. 3 is a schematic block diagram illustrating a configuration of thebase station apparatus 10 according to the present implementation. Thebase station apparatus 10 includes a receive antenna 202, a receiver(receiving step) 204, a higher layer processing unit (higher layerprocessing step) 206, a controller (control step) 208, a transmitter(transmitting step) 210, and a transmit antenna 212. The receiver 204includes a radio receiving unit (radio receiving step) 2040, an FFT unit2041 (FFT step), a demultiplexing unit (demultiplexing step) 2042, achannel estimation unit (channel estimating step) 2043, and a signaldetection unit (signal detecting step) 2044. The transmitter 210includes a coding unit (coding step) 2100, a modulation unit (modulationstep) 2102, a multiple access processing unit (multiple accessprocessing step) 2106, a multiplexing unit (multiplexing step) 2108, aradio transmitting unit (radio transmitting step) 2110, an IFFT unit(IFFT step) 2109, a downlink reference signal generation unit (downlinkreference signal generation step) 2112, and a downlink control signalgeneration unit (downlink control signal generation step) 2113.

The receiver 204 demultiplexes, demodulates, and decodes an uplinksignal (uplink physical channel, uplink physical signal) received fromthe terminal apparatus 10 via the receive antenna 202. The receiver 204outputs a control channel (control information) separated from thereceived signal to the controller 208. The receiver 204 outputs adecoding result to the higher layer processing unit 206. The receiver204 acquires the SR and the ACK/NACK and CSI for the downlink datatransmission included in the received signal.

The radio receiving unit 2040 converts, by down-conversion, an uplinksignal received through the receive antenna 202 into a baseband signal,removes unnecessary frequency components from the baseband signal,controls an amplification level in such a manner as to suitably maintaina signal level, orthogonally demodulates the signal based on an in-phasecomponent and an orthogonal component of the received signal, andconverts the resulting orthogonally-demodulated analog signal into adigital signal. The radio receiving unit 2040 removes a portion of thedigital signal resulting from the conversion, the portion correspondingto a Cyclic Prefix (CP). The FFT unit 2041 performs a fast Fouriertransform on the downlink signal from which CP has been removed(demodulation processing for OFDM modulation), and extracts the signalin the frequency domain.

The channel estimation unit 2043 uses the demodulation reference signalto perform channel estimation for signal detection for the uplinkphysical channel. The channel estimation unit 2043 receives as inputs,from the controller 208, the resources to which the demodulationreference signal is mapped and the demodulation reference signalsequence allocated to each terminal apparatus. The channel estimationunit 2043 uses the demodulation reference signal sequence to measure thechannel state between the base station apparatus 10 and the terminalapparatus 20. The channel estimation unit 2043, in a case of the grantfree access, can identify the terminal apparatus by using the result ofchannel estimation (impulse response and frequency response with thechannel state) (the channel estimation unit 2043 is thus also referredto as an identification unit). The channel estimation unit 2043determines that an uplink physical channel has been transmitted by theterminal apparatus 20 associated with the demodulation reference signalfrom which the channel state has been successfully extracted. In theresource on which the uplink physical channel is determined by thechannel estimation unit 2043 to have been transmitted, thedemultiplexing unit 2042 extracts the signal in the frequency domaininput from the FFT unit 2041 (the signal includes signals from multipleterminal apparatuses 20).

The demultiplexing unit 2042 separates and extracts the uplink physicalchannel (physical uplink control channel, physical uplink sharedchannel) and the like included in the extracted uplink signal in thefrequency domain. The demultiplexing unit outputs the physical uplinkchannel to the signal detection unit 2044/controller 208.

The signal detection unit 2044 uses the channel estimation resultestimated by the channel estimation unit 2043 and the signal in thefrequency domain input from the demultiplexing unit 2042 to detect asignal of uplink data (uplink physical channel) from each terminalapparatus. The signal detection unit 2044 performs detection processingfor a signal from the terminal apparatus 20 associated with thedemodulation reference signal (demodulation reference signal from whichthe channel state has been successfully extracted) allocated to theterminal apparatus 20 determined to have transmitted the uplink data.

FIG. 4 is a diagram illustrating an example of the signal detection unitaccording to the present implementation. The signal detection unit 2044includes an equalization unit 2504, multiple access signal separationunits 2506-1 to 2506-u, IDFT units 2508-1 to 2508-u, demodulation units2510-1 to 2510-u, and decoding units 2512-1 to 2512-u. u, in the case ofthe grant free access, represents the number of terminal apparatusesdetermined by the channel estimation unit 2043 to have transmitteduplink data (for which the channel state has been successfullyextracted) on the same multiple access physical resource or overlappingmultiple access physical resources (at the same time and at the samefrequency). u, in the case of the scheduled access, represents thenumber of terminal apparatuses allowed to transmit uplink data on thesame multiple access physical resource or overlapping multiple accessphysical resources in the DCI (at the same time, for example, OFDMsymbols, slots). Each of the portions constituting the signal detectionunit 2044 is controlled using the configuration related to the grantfree access for each terminal apparatus and input from the controller208.

The equalization unit 2504 generates an equalization weight based on theMMSE standard, from the frequency response input from the channelestimation unit 2043. Here, MRC and ZF may be used for the equalizationprocessing. The equalization unit 2504 multiplies the equalizationweight by the signal (including a signal of each terminal apparatus) inthe frequency domain input from the demultiplexing unit 2042, andextracts the signal in the frequency domain for the terminal apparatus.The equalization unit 2504 outputs the equalized signal in the frequencydomain from each terminal apparatus to the IDFT units 2508-1 to 2508-u.Here, in a case that data is to be detected that is transmitted by theterminal apparatus 20 and that uses the DFTS-OFDM signal waveform, thesignal in the frequency domain is output to the IDFT units 2508-1 to2508-u. In a case that data is to be received that is transmitted by theterminal apparatus 20 and that uses the OFDM signal waveform, the signalin the frequency domain is output to the multiple access signalseparation units 2506-1 to 2506-u.

Each of the IDFT units 2508-1 to 2508-u converts the equalized signal inthe frequency domain from each terminal apparatus into a signal in thetime domain. It's noted that the IDFT units 2508-1 to 2508-u correspondto processing performed by the DFT unit of the terminal apparatus 20.Each of the multiple access signal separation units 2506-1 to 2506-useparates the signal multiplexed by the multi-access signature resourcefrom the signal in the time domain from each terminal apparatus afterconversion with the IDFT (multiple access signal separation processing).For example, in a case that code spreading is used as a multi-accesssignature resource, each of the multiple access signal separation units2506-1 to 2506-u performs inverse spreading processing using thespreading code sequence assigned to each terminal apparatus. It's notedthat, in a case that interleaving is applied as a multi-access signatureresource, deinterleave processing is performed on the signal in the timedomain from each terminal apparatus after conversion with the IDFT(deinterleaving unit).

Each of the demodulation units 2510-1 to 2510-u receives as an input,from the controller 208, pre-notified or predetermined information aboutthe modulation scheme (BPSK, QPSK, 16QAM, 64QAM, 256QAM, and the like)of each terminal apparatus. Based on the information about themodulation scheme, the demodulation units 2510-1 to 2510-u performdemodulation processing on the signal after the multiple access signalseparation, and outputs a Log Likelihood Ratio (LLR) of the bitsequence.

The decoding units 2512-1 to 2512-u receive as an input, from thecontroller 208, pre-notified or predetermined information about thecoding rate. The decoding units 2512-1 to 2512-u perform decodingprocessing on the LLR sequences output from the demodulation units2510-1 to 2510-u, respectively, and output the decoded uplinkdata/uplink control information to the higher layer processing unit 206.In order to perform cancellation processing such as a SuccessiveInterference Canceller (SIC) or turbo equalization, the decoding units2512-1 to 2512-u may generate replicas from external LLRs or post LLRsoutput from the decoding units and perform the cancellation processing.A difference between the external LLR and the post LLR is whether tosubtract, from the decoded LLR, the pre LLR input to each of thedecoding units 2512-1 to 2512-u. In a case that the number ofrepetitions of SIC or turbo equalization is larger than or equal to aprescribed value, each of the decoding units 2512-1 to 2512-u mayperform hard decision on the LLR resulting from the decoding processing,and may output the bit sequence of the uplink data for each terminalapparatus to the higher layer processing unit 206. It's noted that thesignal detection is not limited to that using the turbo equalizationprocessing, and can be replaced with signal detection based on replicageneration and using no interference cancellation, maximum likelihooddetection, EMMSE-IRC, or the like.

The controller 208 controls the receiver 204 and the transmitter 210 byusing the configuration information related to the uplinkreception/configuration information related to the downlink transmissionincluded in the uplink physical channel (physical uplink controlchannel, physical uplink shared channel, or the like) (notified from thebase station apparatus to the terminal apparatus by way of the DCI, RRC,SIB, and the like). The controller 208 acquires the configurationinformation related to the uplink reception/configuration informationrelated to the downlink transmission from the higher layer processingunit 206. In a case that the transmitter 210 transmits the physicaldownlink control channel, the controller 208 generates Downlink Controlinformation (DCI) and outputs the generated information to thetransmitter 210. It's noted that some of the functions of the controller108 can be included in the higher layer processing unit 102. It's notedthat the controller 208 may control the transmitter 210 in accordancewith the parameter of the CP length added to the data signal.

The higher layer processing unit 206 performs processing of layershigher than the physical layer, such as the Medium Access Control (MAC)layer, the Packet Data Convergence Protocol (PDCP) layer, the Radio LinkControl (RLC) layer, and the Radio Resource Control (RRC) layer. Thehigher layer processing unit 206 generates information needed to controlthe transmitter 210 and the receiver 204, and outputs the resultantinformation to the controller 208. The higher layer processing unit 206outputs downlink data (e.g., the DL-SCH), broadcast information (e.g.,the BCH), a hybrid automatic retransmission request (Hybrid AutomaticRepeat request) indicator (HARQ indicator), and the like to thetransmitter 210. The higher layer processing unit 206 receivesinformation, as an input, from the receiver 204, related to a functionof the terminal apparatus (UE capability) supported by the terminalapparatus. For example, the higher layer processing unit 206 receives,through signaling in the RRC layer, information related to the functionof the terminal apparatus.

The information related to the function of the terminal apparatusincludes information indicating whether the terminal apparatus supportsa prescribed function, or information indicating that the terminalapparatus has completed introduction and testing of a prescribedfunction. The information for indicating whether the prescribed functionis supported includes information for indicating whether theintroduction and testing of the prescribed function have been completed.In a case that the terminal apparatus supports the prescribed function,the terminal apparatus transmits information (parameters) for indicatingwhether the prescribed function is supported. In a case that theterminal apparatus does not support the prescribed function, theterminal apparatus may be configured not to transmit information(parameters) for indicating whether the prescribed function issupported. In other words, whether the prescribed function is supportedis notified by whether information (parameters) for indicating whetherthe prescribed function is supported is transmitted. The information(parameters) for indicating whether the prescribed function is supportedmay be notified by using one bit of 1 or 0.

The information related to the function of the terminal apparatusincludes information indicating that the grant free access is supported(information on whether or not each of the UL-TWG-type 1 and theUL-TWG-type 2 is supported). In a case that multiple functionscorresponding to the grant free access are provided, the higher layerprocessing unit 206 can receive information indicating whether the grantfree access is supported on a function-by-function basis. Theinformation indicating that the grant free access is supported includesinformation indicating the multiple access physical resource andmulti-access signature resource supported by the terminal apparatus. Theinformation indicating that the grant free access is supported mayinclude a configuration of a lookup table for the configuration of themultiple access physical resource and the multi-access signatureresource. The information indicating that the grant free access issupported may include some or all of an antenna port, a capabilitycorresponding to multiple tables indicating a scrambling identity andthe number of layers, a capability corresponding to a prescribed numberof antenna ports, and a capability corresponding to a prescribedtransmission mode. The transmission mode is determined by the number ofantenna ports, transmission diversity, the number of layers, and whethersupport of the grant free access and the like are provided.

The information related to the function of the terminal apparatusincludes information indicating that a function related to URLLC issupported. Examples of a DCI format for the uplink dynamic scheduling,the SPS/grant free access, the downlink dynamic scheduling, and the SPSincludes a compact DCI format that has the smaller total number of bitsof the fields in the DCI format, and the information related to thefunction of the terminal apparatus may include information indicatingthat a receiving process on the compact DCI format (blind decoding) issupported. The DCI format is allocated and transmitted in a PDCCH searchspace, and the number of resources that can be used is determined foreach aggregation level. Therefore, as the total number of bits of thefields in the DCI format increases, the coding rate of transmissionbecomes higher, and as the total number of bits of the fields in the DCIformat decreases, the coding rate of transmission becomes lower.Therefore, in a case that high reliability such as that of URLLC isrequired, it is preferable to use the compact DCI format. It's notedthat in LTE or NR, the DCI format is allocated in a predeterminedresource element (search space). Therefore, in a case that the number ofresource elements (aggregation level) is constant, the DCI format with alarger payload size provides a higher coding rate transmission comparedto a DCI format with a smaller payload size, which makes it difficult tosatisfy the high reliability.

The information related to the function of the terminal apparatusincludes information indicating that a function related to URLLC issupported. For example, information may be included that indicatessupport of high reliability detection of the PDCCH by repeatedlytransmitting the information of the DCI format for the uplink ordownlink dynamic scheduling (detection by blind decoding). In a case ofrepeatedly transmitting the information of the DCI format on the PDCCH,the base station apparatus may repeatedly transmit in a prescribed rulethe information of the same DCI format associated with a candidate forblind decoding in a search space to be repeatedly transmitted, anaggregation level, a search space, a CORESET, a BWP, a serving cell, anda slot.

The information related to the function of the terminal apparatus mayinclude information indicating that a function related to carrieraggregation is supported. The information related to the function of theterminal apparatus may include information indicating that the functionsrelated to simultaneous transmission of multiple component carriers(serving cells) (including a case of overlapping in the time domain,overlapping at least in some OFDM symbols) are supported.

The higher layer processing unit 206 manages various types ofconfiguration information about the terminal apparatus. Some of thevarious types of configuration information are input to the controller208. The various types of configuration information are transmitted fromthe base station apparatus 10 via the transmitter 210 using the downlinkphysical channel. The various types of configuration information includeconfiguration information related to the grant free access input fromthe transmitter 210. The configuration information related to the grantfree access includes configuration information about the multiple accessresources (multiple access physical resources and multi-access signatureresources). For example, the configuration information related to thegrant free access may include a configuration related to themulti-access signature resource (configuration related to processingperformed based on a mark for identifying the uplink physical channeltransmitted by the terminal apparatus 20), such as an uplink resourceblock configuration (a starting position of the OFDM symbol to be used,the number of OFDM symbols/the number of resource blocks), aconfiguration of the demodulation reference signal/identification signal(reference signal sequence, cyclic shift, OFDM symbols to be mapped, andthe like), a spreading code configuration (Walsh code, Orthogonal CoverCode (OCC), sparse code, spreading rates of these spreading codes, andthe like), an interleave configuration, a transmit power configuration,a transmit and/or receive antenna configuration, and a transmit and/orreceive beamforming configuration. These multi-access signatureresources may be directly or indirectly associated (linked) with oneanother. The association of the multi-access signature resources isindicated by a multi-access signature process index. The configurationinformation related to the grant free access may include theconfiguration of the look-up table for the configuration of the multipleaccess physical resource and multi-access signature resource. Theconfiguration information related to the grant free access may includesetup of the grant free access, information indicating release, ACK/NACKreception timing information for uplink data signals, retransmissiontiming information for uplink data signals, and the like.

Based on the configuration information related to the grant free accessthat is notified as the control information, the higher layer processingunit 206 manages multiple access resources (multiple access physicalresources, multi-access signature resources) for the uplink data(transport blocks) in grant-free. Based on the configuration informationrelated to the grant free access, the higher layer processing unit 206outputs, to the controller 208, information used to control the receiver204.

The higher layer processing unit 206 outputs generated downlink data(e.g., DL-SCH) to the transmitter 210. The downlink data may include afield storing the UE ID (RNTI). The higher layer processing unit 206adds the CRC to the downlink data. The CRC parity bits are generatedusing the downlink data. The CRC parity bits are scrambled with the UEID (RNTI) allocated to the destination terminal apparatus (thescrambling is also referred to as an exclusive-OR operation, masking, orciphering). However, as described above, the multiple types of RNTI areprovided, which are different depending on the data to be transmitted,and the like.

The higher layer processing unit 206 generates or acquires from a highernode, system information (MIB, SIB) to be broadcasted. The higher layerprocessing unit 206 outputs, to the transmitter 210, the systeminformation to be broadcasted. The system information to be broadcastedcan include information indicating that the base station apparatus 10supports the grant free access. The higher layer processing unit 206 caninclude, in the system information, a portion or all of theconfiguration information related to the grant free access (such as theconfiguration information related to the multiple access resources suchas the multiple access physical resource, the multi-access signatureresource). The uplink system control information is mapped to thephysical broadcast channel/physical downlink shared channel in thetransmitter 210.

The higher layer processing unit 206 generates or acquires from a highernode, and outputs to the transmitter 210, downlink data (transportblocks) to be mapped to the physical downlink shared channel, systeminformation (SIB), an RRC message, a MAC CE, and the like. The higherlayer processing unit 206 can include, in this higher layer signaling,some or all of the configuration information related to the grant freeaccess and parameters indicating setup and/or release of the grant freeaccess. The higher layer processing unit 206 may generate a dedicatedSIB for notifying the configuration information related to the grantfree access.

The higher layer processing unit 206 maps the multiple access resourcesto the terminal apparatuses 20 supporting the grant free access. Thebase station apparatus 10 may hold a lookup table of configurationparameters for the multi-access signature resource. The higher layerprocessing unit 206 allocates each configuration parameter to theterminal apparatuses 20. The higher layer processing unit 206 uses themulti-access signature resource to generate the configurationinformation related to the grant free access for each terminalapparatus. The higher layer processing unit 206 generates a downlinkshared channel including a portion or all of the configurationinformation related to the grant free access for each terminalapparatus. The higher layer processing unit 206 outputs, to thecontroller 208/transmitter 210, the configuration information related tothe grant free access.

The higher layer processing unit 206 configures a UE ID for eachterminal apparatus and notifies the terminal apparatus of the UE ID. Asthe UE ID, a Cell Radio Network Temporary Identifier (RNTI) can be used.The UE ID is used for the scrambling of the CRC added to the downlinkcontrol channel and the downlink shared channel. The UE ID is used forscrambling of the CRC added to the uplink shared channel. The UE ID isused to generate an uplink reference signal sequence. The higher layerprocessing unit 206 may configure a SPS/grant free access-specific UEID. The higher layer processing unit 206 may configure the UE IDseparately depending on whether or not the terminal apparatus supportsthe grant free access. For example, in a case that the downlink physicalchannel is transmitted in the scheduled access and the uplink physicalchannel is transmitted in the grant free access, the UE ID for thedownlink physical channel may be configured separately from the UE IDfor the downlink physical channel. The higher layer processing unit 206outputs the configuration information related to the UE ID to thetransmitter 210/controller 208/receiver 204.

The higher layer processing unit 206 determines the coding rate, themodulation scheme (or MCS), the transmit power, and the like for thephysical channels (physical downlink shared channel, physical uplinkshared channel, and the like). The higher layer processing unit 206outputs the coding rate/modulation scheme/transmit power to thetransmitter 210/controller 208/receiver 204. The higher layer processingunit 206 can include the coding rate/modulation scheme/transmit power inhigher layer signaling.

In a case that the downlink data to be transmitted is generated, thetransmitter 210 transmits the physical downlink shared channel. In acase that the transmitter 210 is transmitting a resource for datatransmission by way of the DL Grant, the transmitter 210 may transmitthe physical downlink shared channel using the scheduled access, andtransmit the physical downlink shared channel using the SPS in a casethat the SPS is activated. The transmitter 210 generates the physicaldownlink shared channel and the demodulation reference signal/controlsignal associated with the physical downlink shared channel inaccordance with the configuration related to the scheduled access/SPSinput from the controller 208.

The coding unit 2100 codes the downlink data input from the higher layerprocessing unit 206 by using the predetermined coding scheme/codingscheme configured by the controller 208 (the coding includesrepetitions). The coding scheme may involve application of convolutionalcoding, turbo coding, Low Density Parity Check (LDPC) coding, Polarcoding, and the like. The LDPC code may be used for data transmission,whereas the Polar code may be used for transmission of the controlinformation. Different error correction coding may be used depending onthe downlink channel to be used. Different error correction coding maybe used depending on the size of the data or control information to betransmitted. For example, the convolution code may be used in a casethat the data size is smaller than a prescribed value, and otherwise thecorrection coding described above may be used. For the coding describedabove, in addition to a coding rate of ⅓, a mother code such as a lowcoding rate of ⅙ or 1/12 may be used. In a case that a coding ratehigher than the mother code is used, the coding rate used for datatransmission may be achieved by rate matching (puncturing). Themodulation unit 2102 modulates coded bits input from the coding unit2100, in compliance with a modulation scheme notified by way of thedownlink control information or a modulation scheme predetermined foreach channel, such as BPSK, QPSK, 16QAM, 64QAM, or 256QAM (themodulation scheme may include π/2 shift BPSK or π/4 shift QPSK).

The multiple access processing unit 2106 performs signal conversion suchthat the base station apparatus 10 can achieve signal detection even ina case that multiple data are multiplexed on a sequence output from themodulation unit 2102 in accordance with multi-access signature resourceinput from the controller 208. In a case that the multi-access signatureresource is configured as spreading, multiplication by the spreadingcode sequence is performed according to the configuration of thespreading code sequence. It's noted that, in a case that interleaving isconfigured as a multi-access signature resource in the multiple accessprocessing unit 2106, the multiple access processing unit 2106 can bereplaced with the interleave unit. The interleave unit performsinterleave processing on the sequence output from the modulation unit2102 in accordance with the configuration of the interleave patterninput from the controller 208. In a case that code spreading andinterleaving are configured as a multi-access signature resource, themultiple access processing unit 2106 of the transmitter 210 performsspreading processing and interleaving. A similar operation is performedeven in a case that any other multi-access signature resource isapplied, and the sparse code or the like may be applied.

In a case that the OFDM signal waveform is used, the multiple accessprocessing unit 2106 inputs the multiple-access-processed signal to themultiplexing unit 2108. The downlink reference signal generation unit2112 generates a demodulation reference signal in accordance with theconfiguration information about the demodulation reference signal inputfrom the controller 208. The configuration information about thedemodulation reference signal/identification signal is used to generatea sequence acquired according to a rule determined in advance, based oninformation such as the number of OFDM symbols notified by the basestation apparatus by way of the downlink control information, the OFDMsymbol position in which the DMRS is allocated, the cyclic shift, andthe time domain spreading.

The multiplexing unit 2108 multiplexes (maps, allocates) the downlinkphysical channel and the downlink reference signal to resource elementsfor each transmit antenna port. In a case that the SCMA is used, themultiplexing unit 2108 allocates the downlink physical channel to theresource elements in accordance with an SCMA resource pattern input fromthe controller 208.

The IFFT unit 2109 performs the Inverse Fast Fourier Transform (IFFT) onthe multiplexed signal to perform OFDM modulation to generate OFDMsymbols. The radio transmitting unit 2110 adds CPs to the OFDM-modulatedsymbols to generate a baseband digital signal. Furthermore, the radiotransmitting unit 2110 converts the baseband digital signal into ananalog signal, removes the excess frequency components from the analogsignal, converts the signal into a carrier frequency by up-conversion,performs power amplification, and transmits the resultant signal to theterminal apparatus 20 via the transmit antenna 212. The radiotransmitting unit 2110 includes a transmit power control function(transmit power controller). The transmit power control followsconfiguration information about the transmit power input from thecontroller 208. It's noted that, in a case that FBMC, UF-OFDM, or F-OFDMis applied, filtering is performed on the OFDM symbols in units ofsubcarriers or sub-bands.

FIG. 5 is a schematic block diagram illustrating a configuration of theterminal apparatus 20 according to the present implementation. The basestation apparatus 10 includes a higher layer processing unit (higherlayer processing step) 102, a transmitter (transmitting step) 104, atransmit antenna 106, a controller (control step) 108, a receive antenna110, and a receiver (receiving step) 112. The transmitter 104 includes acoding unit (coding step) 1040, a modulation unit (modulating step)1042, a multiple access processing unit (multiple access processingstep) 1043, a multiplexing unit (multiplexing step) 1044, a DFT unit(DFT step) 1045, an uplink control signal generation unit (uplinkcontrol signal generating step) 1046, an uplink reference signalgeneration unit (uplink reference signal generating step) 1048, an IFFTunit 1049 (IFFT step), and a radio transmitting unit (radio transmittingstep) 1050. The receiver 112 includes a radio receiving unit (radioreceiving step) 1120, an FFT unit (FFT step) 1121, a channel estimationunit (channel estimating step) 1122, a demultiplexing unit(demultiplexing step) 1124, and a signal detection unit (signaldetecting step) 1126.

The higher layer processing unit 102 performs processing of layershigher than the physical layer, such as the Medium Access Control (MAC)layer, the Packet Data Convergence Protocol (PDCP) layer, the Radio LinkControl (RLC) layer, and the Radio Resource Control (RRC) layer. Thehigher layer processing unit 102 generates information needed to controlthe transmitter 104 and the receiver 112, and outputs the resultantinformation to the controller 108. The higher layer processing unit 102outputs, to the transmitter 104, uplink data (e.g., UL-SCH), uplinkcontrol information, and the like.

The higher layer processing unit 102 transmits information related tothe terminal apparatus, such as the function of the terminal apparatus(UE capability), from the base station apparatus 10 (via the transmitter104). The information related to the terminal apparatus includesinformation indicating that reception/detection/blind decoding of thegrant free access or the compact DCI is supported, informationindicating that reception/detection/blind decoding in the case that theinformation of the DCI format is repeatedly transmitted on the PDCCH issupported, and information indicating whether such functions aresupported on a per function basis. The information indicating that thegrant free access is supported and the information indicating whetherthe grant free access is supported on a per function basis may beidentified depending on the transmission mode.

Based on the various types of configuration information input from thehigher layer processing unit 102, the controller 108 controls thetransmitter 104 and the receiver 112. The controller 108 generates theuplink control information (UCI), based on the configuration informationrelated to the control information input from the higher layerprocessing unit 102, and outputs the generated information to thetransmitter 104.

The transmitter 104 codes and modulates the uplink control information,the uplink shared channel, and the like input from the higher layerprocessing unit 102 for each terminal apparatus, to generate a physicaluplink control channel and a physical uplink shared channel. The codingunit 1040 codes the uplink control information and the uplink sharedchannel by using the predetermined coding scheme/coding scheme notifiedby way of the control information (the coding includes repetitions). Thecoding scheme may involve application of convolutional coding, turbocoding, Low Density Parity Check (LDPC) coding, Polar coding, and thelike. The modulation unit 1042 modulates the coded bits input from thecoding unit 1040 by using a predetermined modulation scheme/a modulationscheme notified by way of the control information, such as the BPSK,QPSK, 16QAM, 64QAM, or 256QAM.

The multiple access processing unit 1043 performs signal conversion suchthat the base station apparatus 10 can achieve signal detection even ina case multiple pieces of data are multiplexed on a sequence output fromthe modulation unit 1042 in accordance with the multi-access signatureresource input from the controller 108. In a case that the multi-accesssignature resource is configured as spreading, multiplication by thespreading code sequence is performed according to the configuration ofthe spreading code sequence. The configuration of the spreading codesequence may be associated with other configurations of the grant freeaccess such as the demodulation reference signal/identification signal.It's noted that the multiple access processing may be performed on thesequence after the DFT processing. It's noted that, in a case thatinterleaving is configured as a multi-access signature resource in themultiple access processing unit 1043, the multiple access processingunit 1043 can be replaced with an interleave unit. The interleave unitperforms interleave processing on the sequence output from the DFT unitin accordance with the configuration of the interleave pattern inputfrom the controller 108. In a case that code spreading and interleavingare configured as a multi-access signature resource, the multiple accessprocessing unit 1043 of the transmitter 104 performs spreadingprocessing and interleaving. A similar operation is performed even in acase that any other multi-access signature resource is applied, and thesparse code or the like may be applied.

The multiple access processing unit 1043 inputs themultiple-access-processed signal to the DFT unit 1045 or themultiplexing unit 1044 depending on whether a DFTS-OFDM signal waveformor an OFDM signal waveform is used. In a case that the DFTS-OFDM signalwaveform is used, the DFT unit 1045 rearranges multiple-access-processedmodulation symbols output from the multiple access processing unit 1043in parallel and then performs Discrete Fourier Transform (DFT)processing on the rearranged modulation symbols. Here, a zero symbolsequence may be added to the modulation symbols, and the DFT may then beperformed to provide a signal waveform in which, instead of a CP, a zerointerval is used for a time signal resulting from IFFT. A specificsequence such as Gold sequence or a Zadoff-Chu sequence may be added tothe modulation symbols, and the DFT may then be performed to provide asignal waveform in which, instead of a CP, a specific pattern is usedfor the time signal resulting from the IFFT. In a case that the OFDMsignal waveform is used, the DFT is not applied, and thus, themultiple-access-processed signal is input to the multiplexing unit 1044.The controller 108 performs control using a configuration of the zerosymbol sequence (the number of bits in the symbol sequence and the like)and a configuration of the specific sequence (sequence seed, sequencelength, and the like), the configurations being included in theconfiguration information related to the grant free access.

The uplink control signal generation unit 1046 adds the CRC to theuplink control information input from the controller 108, to generate aphysical uplink control channel. The uplink reference signal generationunit 1048 generates an uplink reference signal.

The multiplexing unit 1044 maps each of the modulation symbols of theuplink physical channels modulated by the multiple access processingunit 1043 and the DFT unit 1045, the physical uplink control channel,and the uplink reference signal to the resource elements. Themultiplexing unit 1044 maps the physical uplink shared channel and thephysical uplink control channel to resources allocated to each terminalapparatus.

The IFFT unit 1049 performs Inverse Fast Fourier Transform (IFFT) on themodulation symbols of each multiplexed uplink physical channel togenerate OFDM symbols. The radio transmitting unit 1050 adds cyclicprefixes (CPs) to the OFDM symbols to generate a baseband digitalsignal. Furthermore, the radio transmitting unit 1050 converts thedigital signal into an analog signal, removes excess frequencycomponents from the analog signal by filtering, performs up-conversionto the carrier frequency, performs power amplification, and outputs theresultant signal to the transmit antenna 106 for transmission.

The receiver 112 uses the demodulation reference signal to detect thedownlink physical channel transmitted from the base station apparatus10. The receiver 112 detects the downlink physical channel, based on theconfiguration information notified by the base station apparatus by wayof the control information (such as DCI, RRC, SIB). Here, the receiver112 performs blind decoding, for the search space included in the PDCCH,on a candidate that is predetermined or notified by way of higher layercontrol information (RRC signaling). The receiver 112 detects the DCIusing the CRC scrambled with the C-RNTI, the CS-RNTI, the INT-RNTI(including those for the downlink and the uplink), and other RNTI, as aresult of the blind decoding. The blind decoding may be performed by thesignal detection unit 1126 in the receiver 112, or may be performed by acontrol signal detection unit which is not illustrated in the drawing,but may be provided additionally.

The radio receiving unit 1120 converts, by down-conversion, an uplinksignal received through the receive antenna 110 into a baseband signal,removes unnecessary frequency components from the baseband signal,controls the amplification level in such a manner as to suitablymaintain a signal level, performs orthogonal demodulation based on anin-phase component and an orthogonal component of the received signal,and converts the resulting orthogonally-demodulated analog signal into adigital signal. The radio receiving unit 1120 removes a partcorresponding to the CP from the converted digital signal. The FFT unit1121 performs Fast Fourier Transform (FFT) on the signal from which theCPs have been removed, and extracts a signal in the frequency domain.

The channel estimation unit 1122 uses the demodulation reference signalto perform channel estimation for signal detection for the downlinkphysical channel. The channel estimation unit 1122 receives as inputs,from the controller 108, the resources to which the demodulationreference signal is mapped and the demodulation reference signalsequence allocated to each terminal apparatus. The channel estimationunit 1122 uses the demodulation reference signal sequence to measure thechannel state between the base station apparatus 10 and the terminalapparatus 20. The demultiplexing unit 1124 extracts the signal in thefrequency domain input from the radio receiving unit 1120 (the signalincludes signals from multiple terminal apparatuses 20). The signaldetection unit 1126 uses the channel estimation result and the signal inthe frequency domain input from the demultiplexing unit 1124 to detect asignal of downlink data (uplink physical channel).

The higher layer processing unit 102 acquires the downlink data (bitsequence resulting from hard decision) from the signal detection unit1126. The higher layer processing unit 102 performs descrambling(exclusive-OR operation) on the CRC included in the decoded downlinkdata for each terminal apparatus, by using the UE ID (RNTI) allocated toeach terminal. In a case that no error is found in the downlink data asa result of the descrambling error detection, the higher layerprocessing unit 102 determines that the downlink data has been correctlyreceived. It's noted that the signal detection unit 1126 may include acontrol information detection unit detecting control information such asdownlink control information, for example, a DCI format.

FIG. 6 is a diagram illustrating an example of the signal detection unitaccording to the present implementation. The signal detection unit 1126includes an equalization unit 1504, multiple access signal separationunits 1506-1 to 1506-c, demodulation units 1510-1 to 1510-c, anddecoding units 1512-1 to 1512-c.

The equalization unit 1504 generates equalization weights, based on theMMSE standard, from the frequency response input from the channelestimation unit 1122. Here, MRC and ZF may be used for the equalizationprocessing. The equalization unit 1504 multiplies the equalizationweights by the signal in the frequency domain input from thedemultiplexing unit 1124, and extracts the signal in the frequencydomain. The equalization unit 1504 outputs the equalized signal in thefrequency domain to the multiple access signal separation units 1506-1to 1506-c. c represents a numeral of 1 or greater, and represents thenumber of signals received in the same subframe, the same slot, or thesame OFDM symbols, such as PUSCH and PUCCH. Reception of other downlinkchannels may be reception at the same timing.

Each of the multiple access signal separation units 1506-1 to 1506-cseparates the signal multiplexed by the multi-access signature resourcefrom the signal in the time domain (multiple access signal separationprocessing). For example, in a case that code spreading is used as amulti-access signature resource, each of the multiple access signalseparation units 1506-1 to 1506-c performs inverse spreading processingusing the used spreading code sequence. It's noted that, in a case thatinterleaving is applied as a multi-access signature resource,deinterleave processing is performed on the signal in the time domain(deinterleaving unit).

The demodulation units 1510-1 to 1510-c receive as an input, from thecontroller 108, pre-notified or predetermined information about themodulation scheme. Based on the information about the modulation scheme,the demodulation units 1510-1 to 1510-c perform demodulation processingon the signal after the multiple access signal, and outputs a LogLikelihood Ratio (LLR) of the bit sequence.

The decoding units 1512-1 to 1512-c receive as an input, from thecontroller 108, pre-notified or predetermined information about thecoding rate. The decoding units 1512-1 to 1512-c perform decodingprocessing on the LLR sequences output from the demodulation units1510-1 to 1510-c. In order to perform cancellation processing such as aSuccessive Interference Canceller (SIC) or turbo equalization, thedecoding units 1512-1 to 1512-c may generate replicas from external LLRsor post LLRs output from the decoding units and perform the cancellationprocessing. A difference between the external LLR and the post LLR iswhether to subtract, from the decoded LLR, the pre LLR input to each ofthe decoding units 1512-1 to 1512-c.

FIG. 7 illustrates an example of a known uplink data transmission. Thefigure illustrates operations of a timer 1 and a timer 2 that arecontrolled with respect to uplink data transmission and a notificationof an ACK/NACK for the uplink data transmission. A horizontal axis inthe figure represents a time and may be a slot/mini slot (Non-Slot orless than 14 multiple OFDM symbols)/OFDM symbol, and is described hereinas a slot. First, the base station apparatus notifies the uplink grantin a slot n using the DCI format on the PDCCH. The uplink grant isnotified using DCI format 0_0 or 0_1 or is notified using another DCIformat. The uplink grant may include information of the frequencyresource (resource block, resource block group, subcarrier) used by theterminal apparatus for uplink data transmission, and a relative timefrom the slot n to an uplink data transmission timing (e.g. in a casethat the relative time is k, the slot n+k is the uplink datatransmission timing), the number of OFDM symbols and a starting positionof the OFDM symbol to be used in the slot at the uplink datatransmission timing, and the number of continuous OFDM symbols. Theuplink grant may notify the data transmission in multiple slots, and ina case that the relative time indicating the uplink data transmissiontiming is k, in a case that the data transmission is allowed from theslot n+k to the slot n+k+n′, the uplink grant includes information ofn′.

In a case of detecting the uplink grant by the blind decoding of thePDCCH, the terminal apparatus transmits the uplink data at the uplinkdata transmission timing specified by the uplink grant (that is n+2 inthe example of FIG. 7, and the relative time k to the data transmissiontiming is k=2). Here, the uplink grant includes the HARQ process number(e.g., four bits), and the terminal apparatus performs the datatransmission based on the uplink grant corresponding to the HARQ processnumber specified by the uplink grant.

Immediately after the data transmission corresponding to the HARQprocess (PUSCH transmission), the timer 1 for the corresponding HARQprocess is started (invoked/ran). The timer 1 may bedrx-HARQ-RTT-TimerUL, and the drx-HARQ-RTT-TimerUL may be the minimumperiod before the uplink HARQ retransmission grant (UL HARQretransmission grant) is expected by the MAC entity. In other words, aperiod during the timer 1 being running, in which the base stationapparatus performs demodulation/decoding processing on the uplink data,refers to a period in which there is no ACK/NACK for the uplink datatransmission. Thus, the blind decoding may be stopped during a period inwhich the blind decoding may be stopped (a period not during an Onperiod) according to the configuration of the DRX and a period duringthe timer 1 being running. The timer 1 may be configured in a range from0 to 56 OFDM symbols.

In a case that a period of the timer 1 is set to two slots, the timer 1expires at the slot n+4. In a case that timer 1 expires, the timer 2 forthe corresponding HARQ process is started. The timer 2 may bedrx-RetransmissionTimerUL, and drx-RetransmissionTimerUL may be themaximum period until a grant for uplink retransmission is received. FIG.7 illustrates an example in which the timer 2 is set to six slots. Thetimer 2 may be set to any among 10 slots, 11 slots, 12 slots, 14 slots,16 slots, 18 slots, 116 slots, 124 slots, 133 slots, 140 slots, 164slots, 180 slots, 196 slots, 1112 slots, 1128 slots, and 1160 slots.

In a case that the terminal apparatus receives an ACK/NACK for theuplink data transmission during the timer 2 being running (in a slot n+7in the example of FIG. 7), immediately after new data transmission(initial transmission) for the ACK or the same data transmission(retransmission) as the previous transmission for the NACK, the terminalapparatus starts the timer 1 for the corresponding HARQ process andstops the timer 2 for the corresponding HARQ process. Here, the ACK/NACKfor the uplink data transmission can be used in the same format as theDCI format used in the uplink grant, and is notified by the HARQ processID and the NDI in the DCI format. Specifically, in a case that the DCIformat including the HARQ process ID for the data transmission isdetected, a case that a value of the NDI is changed from the NDI valueat the time when the previous DCI format including the same HARQ processID is detected (a case of being toggled in one bit) corresponds to anACK and the detected DCI format is an uplink grant for new datatransmission, and a case that a value of the NDI is the same (a case ofnot being toggled) corresponds to a NACK and the detected DCI format isan uplink grant for retransmission data transmission.

On the other hand, in a case that the ACK/NACK for the uplink datatransmission cannot be detected or the initial transmission orretransmission based on the DCI format including the ACK/NACK is notcompleted until the timer 2 expires, the terminal apparatus may stop theblind decoding in the period during which the blind decoding may beperformed (a period not during an On period) according to theconfiguration of the DRX. In this case, after the period (a periodduring an On period) during which the decoding determined by the periodof the DRX is required is reached, the blind decoding may be started toagain wait for the ACK/NACK for the uplink data transmission. In a casethat the ACK/NACK for the uplink data transmission cannot be detectedeven in a case that the timer 2 expires, the detection of the ACK/NACKtransmitted by the base station apparatus is considered to be failed,and a buffer of the corresponding HARQ process ID may be flushed orretransmission may be performed on a predetermined radio resource (whichmay be a radio resource configured in RRC and activated by the SPS).

FIG. 8 illustrates an example of a stop of uplink data transmissionaccording to the first implementation. In the figure, the base stationapparatus accommodates multiple terminal apparatuses, that include aterminal apparatus to transmit data requiring at least one of lowlatency and high reliability (hereinafter referred to as a URLLCterminal apparatus) and a terminal apparatus to transmit data relativelynot requiring low latency or high reliability (hereinafter referred toas a non-URLLC terminal apparatus or an eMBB terminal apparatus). First,the eMBB terminal apparatus performing eMBB data transmission detects anuplink grant in the DCI format transmitted on the PDCCH, and receives anotification of an allocated PUSCH radio resource. In a case that theeMBB terminal apparatus detects the DCI format with CRC scrambled withan INT-RNTI/UL-INT-RNTI, information on the radio resource indicated inthe DCI format with the CRC scrambled with the INT-RNTI/UL-INT-RNTIincludes information on a radio resource that is unavailable to the eMBBterminal apparatus for uplink data transmission, for example, that isused by another terminal apparatus (URLLC terminal apparatus). The eMBBterminal apparatus maycancel/pre-empt/suspend/stop/drop/defer/break/revoke (hereinafterreferred to as cancel or pre-empt) the data transmission using theallocated PUSCH radio resource in a case that the allocated PUSCH radioresource at least partially overlaps the unavailable radio resource, ora frequency (subcarrier/resource block) of the allocated PUSCH radioresource is adjacent to a frequency of the unavailable radio resource,or a bandwidth (guard band) between the frequency of the allocated PUSCHradio resource and the frequency of the unavailable radio resource isequal to or less than a prescribed bandwidth or a bandwidth notifiedthrough higher layer signaling such as RRC.

FIG. 9 illustrates an example of the stop of the uplink datatransmission according to the first implementation. (a) of FIG. 9illustrates a case that the eMBB terminal apparatus canceling theallocated PUSCH radio resource causes all of the allocated PUSCH radioresources to be cancelled. This enables processing in (a) of FIG. 9 in acase that a process of stopping data transmission of the allocated PUSCHradio resource is ready in time from when the eMBB terminal apparatusreceives the notification of the unavailable radio resource. On theother hand, in (b) of FIG. 9, in a case that the process of stopping thedata transmission of the allocated PUSCH radio resource is not ready intime from when the eMBB terminal apparatus receives the notification ofthe unavailable radio resource, for example, in a case that thenotification of the unavailable radio resource is detected in the OFDMsymbol (one or more OFDM symbols) at the beginning of the same slot asfor the eMBB data transmission, the eMBB terminal apparatus stops thedata transmission before the OFDM symbol for the unavailable radioresource. (b) of FIG. 9 illustrates the case that the data transmissionis continued until immediately before the OFDM symbol for the radioresource that is unavailable to the eMBB terminal apparatus, but thedata transmission may be stopped before the number of OFDM symbols ofthe OFDM symbols for the unavailable radio resource. It's noted that anaspect of the present disclosure can be applied to both cases. In a casethat the eMBB terminal apparatus may continue the data transmission evenafter the OFDM symbols for the unavailable radio resources only in acase that a prescribed condition is satisfied. Specifically, theprescribed condition includes a case that the coding rate is 1 or lessin a case that the OFDM symbol for the unavailable radio resource isconsidered to be a puncture, or at least one or a combination of two ormore of a case that the transmission of the DMRS is possible even in acase of excluding the OFDM symbol for the radio resource, a case ofretransmission data transmission, and a case of a Piggyback (UCI onPUSCH).

The difference between the eMBB terminal apparatus and the URLLCterminal apparatus may include a difference between a case that theuplink grant is received using DCI format 0_0/0_1 and a case that theuplink grant is received using the compact DCI having the number ofcontrol information bits less than DCI format 0_0/0_1, a differencebetween a case of using a table low in a minimum spectral efficiency ofan MCS table used for the data transmission and a case of using a tablehigh in the minimum spectral efficiency, a difference between a case thenumber of entries of the MCS table used for the data transmission is 32(5 bits) and a case of 16 or less (4 bits or less), a difference betweena case of dynamic scheduling and a case of SPS/Configured grant/grantfree access, a difference between a case that the number of HARQprocesses is 16 and a case that the number of HARQ processes is 4, adifference between a case that the number of repetitive datatransmissions is equal to or less than a prescribed value (e.g., equalto or less than 1) and a case that the number of repetitivetransmissions is more than the prescribed value, a difference between acase that a priority of a Logical CHannel (LCH) is low and a case thatthe priority is high, or a difference depending on a QoS Class Indicator(QCI).

FIG. 10 illustrates an example of the uplink data transmission accordingto the first implementation. The figure illustrates a timer that iscontrolled in a case that uplink data transmission is allocated based onthe uplink grant, and thereafter, the DCI for pre-emption is received,and then, the uplink data transmission is cancelled. A horizontal axisin the figure represents a time and may be a slot/mini slot (Non-Slot orless than 14 multiple OFDM symbols)/OFDM symbol, and is described as aslot. First, the base station apparatus notifies the uplink grant in aslot n using the DCI format on the PDCCH. The uplink grant is notifiedusing DCI format 0_0 or 0_1 or is notified using another DCI format. Theuplink grant may include information of the frequency resource (resourceblock, resource block group, subcarrier) used by the terminal apparatusfor uplink data transmission, and a relative time from the slot n to anuplink data transmission timing (e.g. in a case that the relative timeis k, the slot n+k is the uplink data transmission timing), the numberof OFDM symbols and a starting position of the OFDM symbol to be used inthe slot at the uplink data transmission timing, and the number ofcontinuous OFDM symbols. The uplink grant may notify the datatransmission in multiple slots, and in a case that the relative timeindicating the uplink data transmission timing is k, in a case that thedata transmission is allowed from the slot n+k to the slot n+k+n′, theuplink grant includes information of n′.

In a case of detecting the uplink grant by the blind decoding of thePDCCH, the terminal apparatus transmits the uplink data at the uplinkdata transmission timing specified by the uplink grant (that is n+2 inthe example of FIG. 10, and the relative time k to the data transmissiontiming is k=2), but cancels the uplink data transmission in the slot n+2in a case of detecting the notification of the pre-emption on the PDCCHusing the DCI format in the slot n+1. It's noted that the uplink grantincludes the HARQ process number (e.g., four bits), and the terminalapparatus cancels the data transmission based on the uplink grantcorresponding to the HARQ process number specified by the uplink grant.

Immediately after the timing for the corresponding data transmissioncancelled (PUSCH transmission), in a case that the timer 2 for thecorresponding HARQ process is not running, the timer 2 for thecorresponding HARQ process is started (invoked/ran/started). The timer 2may be drx-RetransmissionTimerUL, and drx-RetransmissionTimerUL may bethe maximum period until a grant for uplink retransmission is received.FIG. 10 illustrates an example in which the timer 2 is set to six slots.The timer 2 may be set to any among 10 slots, 11 slots, 12 slots, 14slots, 16 slots, 18 slots, 116 slots, 124 slots, 133 slots, 140 slots,164 slots, 180 slots, 196 slots, 1112 slots, 1128 slots, and 1160 slots,or may be set to any among the numbers of slots which are not pre-emptedand different (from the operation in FIG. 7). The period of the timer 2may be set for each of the case that the uplink data transmission iscanceled based on the pre-emption (FIG. 10) and the case that the uplinkdata transmission is transmitted (FIG. 7). For example, 16 slots may beset in the case that the uplink data is transmitted, and 10 slots may beset in the case that the uplink data transmission is canceled.

In a case that the terminal apparatus receives the uplink grant for thecorresponding data transmission cancelled (pre-empted data) during thetimer 2 being running (in the slot n+5 in the example of FIG. 10), theterminal apparatus, immediately after transmitting the datacorresponding to the cancelled HARQ process ID, starts the timer 1 forthe corresponding HARQ process and stops the timer 2 for thecorresponding HARQ process. Here, the HARQ process ID for the uplinkdata transmission is notified using the DCI format used for the uplinkgrant. The timer 1 may be drx-HARQ-RTT-TimerUL, and thedrx-HARQ-RTT-TimerUL may be the minimum period before the uplink HARQretransmission grant (UL HARQ retransmission grant) is expected by theMAC entity. In other words, a period during the timer 1 being running,in which the base station apparatus performs demodulation/decodingprocessing on the uplink data, refers to a period in which there is noACK/NACK for the uplink data transmission. Thus, the blind decoding maybe stopped during a period in which the blind decoding may be stopped (aperiod not during an On period) according to the configuration of theDRX and a period during the timer 1 running. The timer 1 may beconfigured in a range from 0 to 56 OFDM symbols. Accordingly, in a casethat the uplink data transmission in FIG. 10 is canceled, the basestation apparatus does not need to demodulate/decode the uplink data,and thus, the timer 2 is invoked (ran) without using the timer 1.

FIG. 11 illustrates an example of uplink data retransmission accordingto the first implementation. The figure differs from FIG. 10 in that thecancelled uplink data is retransmission. The initial transmission may beperformed in the case that the timer 1 expires and the timer 2 isrunning in the example of FIG. 7, or in the case that the timer 2 isrunning in the example of FIG. 10. It's noted that in a case that theuplink data transmission in FIG. 10 is canceled, retransmission (the NDIis not toggled) may be performed, or the initial transmission (NDI istoggled) may be performed, to either of which aspect of the presentdisclosure can be applied.

In FIG. 11, in a case that the timer 2 is running in the slot n owing tothe initial transmission or the retransmission and the cancellation ofthe uplink data transmission, the base station apparatus notifies theuplink grant for retransmission on the PDCCH using the DCI format. Theuplink grant is notified using DCI format 0_0 or 0_1 or is notifiedusing another DCI format. The uplink grant may include information ofthe frequency resource (resource block, resource block group,subcarrier) used by the terminal apparatus for uplink data transmission,and a relative time from the slot n to an uplink data transmissiontiming (e.g. in a case that the relative time is k, the slot n+k is theuplink data transmission timing), the number of OFDM symbols and astarting position of the OFDM symbol to be used in the slot at theuplink data transmission timing, and the number of continuous OFDMsymbols. The uplink grant may notify the data transmission in multipleslots, and in a case that the relative time indicating the uplink datatransmission timing is k, in a case that the data transmission isallowed from the slot n+k to the slot n+k+n′, the uplink grant includesinformation of n′.

In a case of detecting the uplink grant for retransmission by the blinddecoding of the PDCCH, the terminal apparatus transmits the uplink dataat the uplink data transmission timing specified by the uplink grant(that is n+2 in the example of FIG. 11, and the relative time k to thedata transmission timing is k=2), but cancels the uplink datatransmission in the slot n+2 in a case of detecting the notification ofthe pre-emption on the PDCCH using the DCI format in the slot n+1. It'snoted that the uplink grant includes the HARQ process number (e.g., fourbits), and the terminal apparatus cancels the data transmission based onthe uplink grant corresponding to the HARQ process number specified bythe uplink grant.

Immediately after the timing for the corresponding data transmissioncancelled (PUSCH transmission), in a case that the timer 2 for thecorresponding HARQ process is running, the timer 2 for the correspondingHARQ process is started (restarted). The timer 2 may bedrx-RetransmissionTimerUL, and drx-RetransmissionTimerUL may be themaximum period until a grant for uplink retransmission is received. FIG.11 illustrates an example in which the timer 2 is set to six slots. Thetimer 2 may be set to any among 10 slots, 11 slots, 12 slots, 14 slots,16 slots, 18 slots, 116 slots, 124 slots, 133 slots, 140 slots, 164slots, 180 slots, 196 slots, 1112 slots, 1128 slots, and 1160 slots, ormay be set to any among the numbers of slots which are not pre-emptedand different (from the operation in FIG. 7). The period of the timer 2may be set for each of the case that the uplink data transmission iscanceled based on the pre-emption (FIG. 11) and the case that the uplinkdata transmission is transmitted (FIG. 7). For example, 16 slots may beset in the case that the uplink data is transmitted, and 10 slots may beset in the case that the uplink data transmission is canceled.

In a case that the terminal apparatus receives the uplink grant for thecorresponding data transmission cancelled (pre-empted data) during thetimer 2 being running (in the slot n+5 in the example of FIG. 11), theterminal apparatus, immediately after transmitting the datacorresponding to the cancelled HARQ process ID, starts the timer 1 forthe corresponding HARQ process and stops the timer 2 for thecorresponding HARQ process. Here, the HARQ process ID for the uplinkdata transmission is notified using the DCI format used for the uplinkgrant. The timer 1 may be drx-HARQ-RTT-TimerUL, and thedrx-HARQ-RTT-TimerUL may be the minimum period before the uplink HARQretransmission grant (UL HARQ retransmission grant) is expected by theMAC entity. In other words, a period during the timer 1 being running,in which the base station apparatus performs demodulation/decodingprocessing on the uplink data, refers to a period in which there is noACK/NACK for the uplink data transmission. Thus, the blind decoding maybe stopped during a period in which the blind decoding may be stopped (aperiod not during an On period) according to the configuration of theDRX and a period during the timer 1 running. The timer 1 may beconfigured in a range from 0 to 56 OFDM symbols. Accordingly, in a casethat the uplink data transmission in FIG. 11 is canceled, the basestation apparatus does not need to demodulate/decode the uplink data,and thus, the timer 2 is invoked (ran) without using the timer 1.

FIG. 12 illustrates an example of the stop of the uplink datatransmission according to the first implementation. The figureillustrates a timer that is controlled in a case that uplink datatransmission is allocated based on the uplink grant, and thereafter, theDCI for pre-emption is received, and then, the uplink data transmissionis cancelled. A horizontal axis in the figure represents a time and maybe a slot/mini slot (Non-Slot or less than 14 multiple OFDMsymbols)/OFDM symbol, and is described as a slot. First, the basestation apparatus notifies the uplink grant in a slot n using the DCIformat on the PDCCH. The uplink grant is notified using DCI format 0_0or 0_1 or is notified using another DCI format. The uplink grant mayinclude information of the frequency resource (resource block, resourceblock group, subcarrier) used by the terminal apparatus for uplink datatransmission, and a relative time from the slot n to an uplink datatransmission timing (e.g. in a case that the relative time is k, theslot n+k is the uplink data transmission timing), the number of OFDMsymbols and a starting position of the OFDM symbol to be used in theslot at the uplink data transmission timing, and the number ofcontinuous OFDM symbols. The uplink grant may notify the datatransmission in multiple slots, and in a case that the relative timeindicating the uplink data transmission timing is k, in a case that thedata transmission is allowed from the slot n+k to the slot n+k+n′, theuplink grant includes information of n′.

In a case of detecting the uplink grant by the blind decoding of thePDCCH, the terminal apparatus transmits the uplink data at the uplinkdata transmission timing specified by the uplink grant (that is n+2 inthe example of FIG. 12, and the relative time k to the data transmissiontiming is k=2), but cancels the uplink data transmission in the slot n+2in a case of detecting the notification of the pre-emption on the PDCCHusing the DCI format in the slot n+1. It's noted that the uplink grantincludes the HARQ process number (e.g., four bits), and the terminalapparatus cancels the data transmission based on the uplink grantcorresponding to the HARQ process number specified by the uplink grant.

In FIG. 12, in a case that the PDCCH indicates the uplink grant for theinitial transmission (uplink new transmission), a timer 3 is started(invoked/ran/started). The timer 3 may be drx-InactivityTimer, anddrx-InactivityTimer may be a period after a PDCCH occasion for the PDCCH(uplink grant or downlink grant) indicating the initial uplink ordownlink user data transmission of the MAC entity. Next, in a case ofdetecting the notification of the pre-emption on the PDCCH using the DCIformat in the slot n+1 when timer 3 is running, the timer 3 is restartedin the same manner as in receiving the uplink grant. This is in order toavoid a matter in which the base station apparatus may continuouslytransmit the uplink grant or the downlink grant, and in the case thatany grant is received, in a case that the timer 3 is in the periodduring which the blind decoding may not be performed (a period notduring an On period) according to the configuration of the DRX, thegrant cannot be continuously detected. Thus, in a case that the timer 3expires immediately after detecting the DCI format for the pre-emption,the terminal apparatus may stop the blind decoding. Therefore, in thepresent implementation, the notification of the pre-emption is handledsimilarly to the grant, and a period until expiration can be reserved byrestarting the timer 3. It's noted that drx-InactivityTimer may be setany among {1 ms, 2 ms, 3 ms, 4 ms, 5 ms, 6 ms, 8 ms, 10 ms, 20 ms, 30ms, 40 ms, 50 ms, 60 ms, 80 ms, 100 ms, 200 ms, 300 ms, 400 ms, 500 ms,600 ms, 800 ms, 1000 ms, 1200 ms, 1600 ms}. The timer 3 may respectivelyhave a setting of the period of the timer for detecting the uplink grantand a setting of the period of the timer for detecting the pre-emption,and the period of the timer for detecting the uplink grant may be 10 msand the period of the timer for detecting the pre-emption may be 20 ms.

It's noted that the notification of the pre-emption using the DCIdescribed in the present implementation may be a notification using thesame number of bits as DCI format 0_0 with the CRC scrambled withINT-RNTI/UL-INT-RNTI, a notification using the same number of bits asDCI format 0_1 with the CRC scrambled with INT-RNTI/UL-INT-RNTI, anotification using the same number of bits as DCI format 2_1 with theCRC scrambled with UL-INT-RNTI different from INT-RNTI, a notificationspecific to the UE using the number of bits of a DCI format with the CRCscrambled with INT-RNTI/UL-INT-RNTI defined to be dedicated to anotification of the uplink pre-emption, a notification to a group of UEto which the same INT-RNTI/UL-INT-RNTI is notified in advance, or anotification to the UE in the same serving cell/BWP.

In the present implementation, the timer is controlled not only in thecase that the terminal apparatus performs the uplink data transmission,but also in the case that the terminal apparatus cancels the uplink datatransmission. As a result, the notification of the uplink grant can beefficiently realized in the case that the uplink data transmission iscanceled, and an increase in power consumption caused by the terminalapparatus continuing to perform the blind decoding and the unnecessarySR transmission can be avoided.

Second Implementation

The present implementation describes a method for notifying allocationinformation of the uplink data transmission cancelled using the DCIformat notifying of the pre-emption. A communication system according tothe present implementation includes the base station apparatus 10 andthe terminal apparatus 20 illustrated in FIGS. 3, 4, 5, and 6.Differences from/additions to the first implementation will be mainlydescribed below.

In the previous implementation, the pre-emption using the DCI isnotified to cancel the uplink data transmission, but the presentimplementation describes an example in which an alternate resource fortransmitting the pre-empted data is notified together with thenotification of the pre-emption using the DCI.

FIG. 13 illustrates an example of an uplink data transmission accordingto a second implementation. The figure illustrates control of thealternate resource for transmitting the pre-empted data in a case thatuplink data transmission is allocated based on the uplink grant, andthereafter, the DCI for pre-emption is received, and then, the uplinkdata transmission is cancelled. A horizontal axis in the figurerepresents a time and may be a slot/mini slot (Non-Slot or less than 14multiple OFDM symbols)/OFDM symbol, and is described as a slot. First,the base station apparatus notifies the uplink grant in a slot n usingthe DCI format on the PDCCH. The uplink grant is notified using DCIformat 0_0 or 0_1 or is notified using another DCI format. The uplinkgrant may include information of the frequency resource (resource block,resource block group, subcarrier) used by the terminal apparatus foruplink data transmission, and a relative time from the slot n to anuplink data transmission timing (e.g. in a case that the relative timeis k, the slot n+k is the uplink data transmission timing), the numberof OFDM symbols and a starting position of the OFDM symbol to be used inthe slot at the uplink data transmission timing, and the number ofcontinuous OFDM symbols. The uplink grant may notify the datatransmission in multiple slots, and in a case that the relative timeindicating the uplink data transmission timing is k, in a case that thedata transmission is allowed from the slot n+k to the slot n+k+n′, theuplink grant includes information of n′.

In a case of detecting the uplink grant by the blind decoding of thePDCCH, the terminal apparatus transmits the uplink data at the uplinkdata transmission timing specified by the uplink grant (that is n+2 inthe example of FIG. 13, and the relative time k to the data transmissiontiming is k=2), but cancels the uplink data transmission in the slot n+2in a case of detecting the notification of the pre-emption on the PDCCHusing the DCI format in the slot n+1. It's noted that the uplink grantincludes the HARQ process number (e.g., four bits), and the terminalapparatus cancels the data transmission based on the uplink grantcorresponding to the HARQ process number specified by the uplink grant.

Furthermore, the DCI format for the detected pre-emption notificationmay include information on the timing (time domain resource assignment)for transmitting the uplink data transmission canceled in the slot n+2.In this case, the timing information may notify a relative time L fromthe slot n+1 of the pre-emption notification. In the case of FIG. 13,L=3 holds, and the terminal apparatus performs, in slot n+4, the uplinkdata transmission cancelled in the slot n+2. It's noted that the timinginformation may be a relative time from the slot (slot n) in which theuplink grant for the uplink data transmission cancelled is detected.It's noted that the timing information may be a relative time from theslot (slot n+2) for the uplink data transmission cancelled. Here, theterminal apparatus may use transmission parameters notified using DCIformat 0_0 or 0_1 in the slot n (frequency domain resource assignment,MCS, frequency hopping flag, RV, NDI, HARQ process number, TPC commandfor PUSCH, UL/SUL (Supplemental UL) indicator, or the like) to transmitthe uplink data by changing only the transmission timing.

Furthermore, the DCI format for the detected pre-emption notificationmay include frequency domain resource assignment or MCS, besides theinformation on the timing for transmitting the uplink data transmissioncanceled in the slot n+2. This is in order to allow the frequency domainresource assignment and the MCS to be re-specified in accordance withscheduling conditions and the like because the timing of uplink datatransmission is shifted in the slot n+2.

In the present implementation, in the case that the terminal apparatuscancels the uplink data transmission, the alternate radio resource foruplink data transmission cancelled is notified using the DCI for thepre-emption. As a result, the notification of the uplink grant can beefficiently realized in the case that the uplink data transmission iscanceled, and an increase in power consumption caused by the terminalapparatus continuing to perform the blind decoding and the unnecessarySR transmission can be avoided.

Third Implementation

The present implementation describes a method for notifying allocationinformation of the uplink data transmission cancelled using the DCIformat notifying of the pre-emption. A communication system according tothe present implementation includes the base station apparatus 10 andthe terminal apparatus 20 illustrated in FIGS. 3, 4, 5, and 6.Differences from/additions to the first implementation will be mainlydescribed below.

FIG. 14 illustrates an example of an uplink data transmission accordingto a third implementation. The figure illustrates control of thealternate resource for transmitting the pre-empted data in a case thatuplink data transmission is allocated based on the uplink grant, andthereafter, the DCI for pre-emption is received, and then, the uplinkdata transmission is cancelled. A horizontal axis in the figurerepresents a time and may be a slot/mini slot (Non-Slot or less than 14multiple OFDM symbols)/OFDM symbol, and is described as a slot. First,the base station apparatus notifies the uplink grant in a slot n usingthe DCI format on the PDCCH. The uplink grant is notified using DCIformat 0_0 or 0_1 or is notified using another DCI format. The uplinkgrant may include information of the frequency resource (resource block,resource block group, subcarrier) used by the terminal apparatus foruplink data transmission, and a relative time from the slot n to anuplink data transmission timing (e.g. in a case that the relative timeis k, the slot n+k is the uplink data transmission timing), the numberof OFDM symbols and a starting position of the OFDM symbol to be used inthe slot at the uplink data transmission timing, and the number ofcontinuous OFDM symbols. The uplink grant may notify the datatransmission in multiple slots, and in a case that the relative timeindicating the uplink data transmission timing is k, in a case that thedata transmission is allowed from the slot n+k to the slot n+k+n′, theuplink grant includes information of n′.

In a case of detecting the uplink grant by the blind decoding of thePDCCH, the terminal apparatus transmits the uplink data at the uplinkdata transmission timing specified by the uplink grant (that is n+2 inthe example of FIG. 14, and the relative time k to the data transmissiontiming is k=2), but cancels the uplink data transmission in the slot n+2in a case of detecting the notification of the pre-emption on the PDCCHusing the DCI format in the slot n+1. It's noted that the uplink grantincludes the HARQ process number (e.g., four bits), and the terminalapparatus cancels the data transmission based on the uplink grantcorresponding to the HARQ process number specified by the uplink grant.

Furthermore, the DCI format for the detected pre-emption notificationmay include timing information notifying the uplink grant to reallocatethe radio resource for transmitting the cancelled data. In this case,the timing information may notify a relative time J from the slot n+1 ofthe pre-emption notification. In the case of FIG. 14, J=3 holds, and theterminal apparatus performs, in the slot n+4, detection of the uplinkgrant notifying the radio resources for the uplink data transmissioncancelled in the slot n+2. It's noted that the timing information may bea relative time from the slot (slot n) in which the uplink grant for theuplink data transmission cancelled is detected. It's noted that thetiming information may be a relative time from the slot (slot n+2) forthe uplink data transmission cancelled. Here, the terminal apparatusdetects the uplink grant using DCI format 0_0 or 0_1 in the slot n+4,and transmits the pre-empted data based on the information on the DCIdetected in the slot n+4 (in the slot n+5).

In the present implementation, in the case that the terminal apparatuscancels the uplink data transmission, the timing for the uplink grant isnotified for the alternate radio resource for the uplink datatransmission cancelled that is notified using the DCI for thepre-emption. As a result, the notification of the uplink grant can beefficiently realized in the case that the uplink data transmission iscanceled, and an increase in power consumption caused by the terminalapparatus continuing to perform the blind decoding and the unnecessarySR transmission can be avoided.

It's noted that the implementations herein may be applied in combinationwith multiple implementations, or each implementation only may beapplied.

A program running on an apparatus according to an aspect of the presentdisclosure may serve as a program that controls a Central ProcessingUnit (CPU) and the like to cause a computer to operate in such a manneras to realize the functions of the above-described implementationaccording to an aspect of the present disclosure. Programs or theinformation handled by the programs are temporarily read into a volatilememory, such as a Random Access Memory (RAM) while being processed, orstored in a non-volatile memory, such as a flash memory, or a Hard DiskDrive (HDD), and then read by the CPU to be modified or rewritten, asnecessary.

It's noted that the apparatuses in the above-described implementationsmay be partially enabled by a computer. In that case, a program forrealizing the functions of the implementations may be recorded on acomputer readable recording medium. This configuration may be realizedby causing a computer system to read the program recorded on therecording medium for execution. It is assumed that the “computer system”refers to a computer system built into the apparatuses, and the computersystem includes an operating system and hardware components such as aperipheral device. Furthermore, the “computer-readable recording medium”may be any of a semiconductor recording medium, an optical recordingmedium, a magnetic recording medium, and the like.

Moreover, the “computer-readable recording medium” may include a mediumthat dynamically retains a program for a short period of time, such as acommunication line that is used for transmission of the program over anetwork such as the Internet or over a communication line such as atelephone line, and may also include a medium that retains a program fora fixed period of time, such as a volatile memory within the computersystem for functioning as a server or a client in such a case.Furthermore, the above-described program may be one for realizing someof the above-described functions, and also may be one capable ofrealizing the above-described functions in combination with a programalready recorded in a computer system.

Furthermore, each functional block or various characteristics of theapparatuses used in the above-described implementations may beimplemented or performed on an electric circuit, that is, typically anintegrated circuit or multiple integrated circuits. An electric circuitdesigned to perform the functions described in the present specificationmay include a general-purpose processor, a Digital Signal Processor(DSP), an Application Specific Integrated Circuit (ASIC), a FieldProgrammable Gate Array (FPGA), or other programmable logic devices,discrete gates or transistor logic, discrete hardware components, or acombination thereof. The general-purpose processor may be amicroprocessor or may be a processor of known type, a controller, amicro-controller, or a state machine instead. The above-mentionedelectric circuit may include a digital circuit, or may include an analogcircuit. Furthermore, in a case that with advances in semiconductortechnology, a circuit integration technology appears that replaces thepresent integrated circuits, it is also possible to use an integratedcircuit based on the technology.

It's noted that the present disclosure is not limited to theabove-described implementations. In the implementation, apparatuses havebeen described as an example, but the present disclosure is not limitedto these apparatuses, and is applicable to a terminal apparatus or acommunication apparatus of a fixed-type or a stationary-type electronicapparatus installed indoors or outdoors, for example, an AV apparatus, akitchen apparatus, a cleaning or washing machine, an air-conditioningapparatus, office equipment, a vending machine, and other householdapparatuses.

The implementations of the present disclosure have been described indetail above referring to the drawings, but the specific configurationis not limited to the implementations and includes, for example, anamendment to a design that falls within the scope that does not departfrom the gist of the present disclosure. Furthermore, variousmodifications are possible within the scope of one aspect of the presentdisclosure defined by claims, and implementations that are made bysuitably combining technical means disclosed according to the differentimplementations are also included in the technical scope of the presentdisclosure. Furthermore, a configuration in which constituent elements,described in the respective implementations and having mutually the sameeffects, are substituted for one another is also included in thetechnical scope of the present disclosure.

INDUSTRIAL APPLICABILITY

An aspect of the present disclosure can be utilized, for example, in acommunication system, communication equipment (for example, a cellularphone apparatus, a base station apparatus, a wireless LAN apparatus, ora sensor device), an integrated circuit (for example, a communicationchip), or a program.

REFERENCE SIGNS LIST

-   -   10 Base station apparatus    -   20-1 to 20-n 1 Terminal apparatus    -   10 a Range in which the base station apparatus 10 can connect to        the terminal apparatus    -   102 Higher layer processing unit    -   104 Transmitter    -   106 Transmit antenna    -   108 Controller    -   110 Receive antenna    -   112 Receiver    -   1040 Coding unit    -   1042 Modulation unit    -   1043 Multiple access processing unit    -   1044 Multiplexing unit    -   1046 Uplink control signal generation unit    -   1048 Uplink reference signal generation unit    -   1049 IFFT unit    -   1050 Radio transmitting unit    -   1120 Radio receiving unit    -   1121 FFT unit    -   1122 Channel estimation unit    -   1124 Demultiplexing unit    -   1126 Signal detection unit    -   1504 Equalization unit    -   1506-1 to 1506-c Multiple access signal separation unit    -   1510-1 to 1510-c Demodulation unit    -   1512-1 to 1512-c Decoding unit    -   202 Receive antenna    -   204 Receiver    -   206 Higher layer processing unit    -   208 Controller    -   210 Transmitter    -   212 Transmit antenna    -   2100 Coding unit    -   2102 Modulation unit    -   2106 Multiple access processing unit    -   2108 Multiplexing unit    -   2109 IFFT unit    -   2110 Radio transmitting unit    -   2112 Downlink reference signal generation unit    -   2113 Downlink control signal generation unit    -   2040 Radio receiving unit    -   2041 FFT unit    -   2042 Demultiplexing unit    -   2043 Channel estimation unit    -   2044 Signal detection unit    -   2504 Equalization unit    -   2506-1 to 2506-u Multiple access signal separation unit    -   2508-1 to 2508-u IDFT unit    -   2510-1 to 2510-u Demodulation unit    -   2512-1 to 2512-u Decoding unit

What is claimed is:
 1. A terminal apparatus for communicating with abase station apparatus, the terminal apparatus comprising: a controlinformation detection unit configured to detect a first downlink controlinformation (DCI) format and a second DCI format; and a transmitterconfigured to perform uplink data transmission based on the first DCIformat or cancel, by using the second DCI format, a resource scheduled,wherein: the control information detection unit detects an uplink grantfor the uplink data transmission using the first DCI format, in a caseof performing corresponding uplink data transmission based on the uplinkgrant, the transmitter, after the uplink data transmission, starts afirst timer for a corresponding hybrid automatic repeat request (HARQ)process and stops a second timer for the corresponding HARQ process, andin a case that the first timer expires, the transmitter starts thesecond timer for the corresponding HARQ process, and in a case thatcancellation of the uplink data transmission based on the uplink grantusing the second DCI format is detected, the transmitter, at a timingfor the corresponding data transmission canceled, restarts the secondtimer in a case that the first timer for the corresponding HARQ processexpires and the second timer is running, and starts the second timer ina case that the second timer is not running.
 2. The terminal apparatusaccording to claim 1, wherein different periods are configured for asecond timer configured to start after the first timer expires and for asecond timer configured to start at the timing for the correspondingdata transmission canceled.
 3. The terminal apparatus according to claim1, wherein a third timer is provided, the third timer being configuredto start in a case that the uplink grant using the first DCI format isdetected, and in a case that cancellation of the uplink datatransmission based on the uplink grant using the second DCI format isdetected, the third timer is restarted.
 4. The terminal apparatusaccording to claim 3, wherein different periods are configured for athird timer configured to start in a case that the uplink grant usingthe first DCI format is detected and a third timer configured to restartin a case that cancellation of the uplink data transmission based on theuplink grant using the second DCI format is detected.
 5. The terminalapparatus according to claim 1, wherein in a case that cancellation ofthe uplink data transmission based on the uplink grant using the secondDCI format is detected, the uplink data transmission is performed basedon a transmission timing included in the second DCI format and atransmission parameter included in the first DCI format.
 6. The terminalapparatus according to claim 5, wherein in a case that cancellation ofthe uplink data transmission based on the uplink grant using the secondDCI format is detected, the uplink data transmission is performed basedon a transmission timing and a modulation and coding scheme (MCS), and afrequency domain resource assignment included in the second DCI format,and a transmission parameter that is not included in the second DCIformat, but included in the first DCI format.
 7. The terminal apparatusaccording to claim 1, wherein in a case of cancellation of the uplinkdata transmission based on the uplink grant using the second DCI formatis detected, an uplink grant for reallocation is detected based on anotification timing for the uplink grant included in the second DCIformat.